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Is the BANS concept for malignant melanoma valid?
Is the BANS Concept for Malignant Melanoma Valid?
John E. Woods, MD, Rochester, Minnesota William F. Taylor, PhD, Rochester, Minnesota Douglas J. Pritchard, MD, Rochester, Minnesota Franklin H. Sim, MD, Rochester, Minnesota John C. Ivins, MD, Rochester, Minnesota Erik J. Bergstralh, MS, Rochester, Minnesota
In 1982, Day and co-authors [I] analyzed their data on 203 patients with malignant melanoma from 1972 to 1977 who had lesions ranging from 0.76 to 1.69 mm in thickness. They presented the concept that lesions of the upper back, upper posterior arms, posterior neck, and posterior scalp (the BANS areas) had a significantly worse prognosis than lesions of similar thickness located at other sites (16 percent and 0.7 percent, respectively, for the period of study). To our knowledge, this thesis has not been tested and corroborated by other groups, although Urist et al [Z] reported a worse prognosis for patients with lesions on the scalp and neck than for those with facial and ear lesions in a recent report on stage I malignant melanoma of the head and neck. To test the BANS theory, we analyzed data from 1973 to 1981 on patients with stage I malignant disease seen at the Mayo Clinic. Material and Methods There were 648 patients with stage I malignant melanoma seen at our institution from the beginning of 1973 to the end of 1981, but only those whose records had complete information with respect to thickness, level of penetration, and morphologic type, and those seen with their first melanomatous lesion were included. Thickness of the lesions was not known in 136 of the earlier patients. Patients who underwent delayed prophylactic nodal dissection were excluded to provide a clear comparison between those who had immediate wide excision and prophylactic node dissection and those who underwent excision alone. A total of 423 patients were analyzed in this study (191 From the Divisions of Plastic Surgery, Orthopedic Surgery, Biostatistics. and Medical Research Statistics, Mayo Clinic, Rochester, Minnesota. Requests for reprints should be addressed to John E. Woods, MD. Division of Plastic Surgery, Mayo Clinic, Rochester, Minnesota 55905. Presented at the 31st Annual Meeting of the Society of Head and Neck Surgeons, Dorado, Puerto Rico, May 5-8. 1985.
452
women, 45 percent and 232 men, 55 percent). The anatomic distribution of the lesions was as follows: In 111 patients (26 percent), the site was the BANS area; in 92 patients (22 percent), other areas of the head and neck; in 86 patients (20 percent), the trunk; and in the remaining 134 patients (32 percent), the arms and legs. One patient (less than 1 percent of total group) was in the 9 years or younger age group, 9 patients (2 percent) were in the 10 to 19 year age group, 47 patients (11 percent) were in the 20 to 29 year age group, 63 patients (15 percent) were in the 30 to 39 year age group, 89 patients (21 percent) were in the 40 to 49 year age group, 101 patients (24 percent) were in the 50 to 59 year age group, 69 patients (16 percent) were in the 60 to 69 year age group, 35 patients (8 percent) were in the 70 to 79 year age group, 8 patients (2 percent) were in the 80 to 89 year age group, and 1 patient (less than 1 percent of total) was in the 90 years or older age group. Morphologic classification included 39 patients with malignant lentigo or other forms, 297 with superficial spreading, and 87 patients with nodular melanoma. The primary lesions penetrated to level 2 or 3 in 248 patients, whereas 175 patients had lesions that penetrated to levels 4 or 5. Distribution of patients according to thickness of the lesions was as follows: In 157 patients (37 percent), the thickness was 0 to 0.75 mm; in 120 patients (28 percent), 0.76 to 1.69 mm; in 107 patients (25 percent), 1.70 to 3.65 mm; and in 39 patients (9 percent), 3.66 mm or thicker. Wide local excision alone was employed in 271 patients (64 percent), and immediate prophylactic node dissection in addition to wide local excision was carried out in 152 patients (36 percent). Follow-up for patients last known alive ranged from less than 1 year in less than 1 percent to over 10 years in 4 percent, with a median follow-up of 5 years. The method of Kaplan and Meier [3] was used to estimate the percentage of surviving patients. At various times a#er surgery, deaths from other causes were considered withdrawals from the study. The log-rank test was used to compare various subgroups based on survival rates during the 4 years after surgery. The first 4 postop-
The American Journal of Surgewy
The BANS Concept for Malignant Melanoma
90
100 80
1 ‘T
’
-----
:., . ..
-.
‘..,
70
X.,
60 % *"rYI"aI
t
--.--_---
‘\
'. _. ----a______-_-_---'....._ ..... ........._
1 ~~~~~~~~~~
30 ' 0
1
2
3
4
5
6
7
6
0
1
2
3
Figure 1. Patlent survival after surgery tar stage I malignant melanoma.
:““‘” 80
-
70
-
60
-
50
-
4
5
6
7
a
years aftersurgery
years altersurgery
’
..........._-...._
Figure 2. Survival of patients with stage I melanoma by thickness (mm) of primary lesion.
...........................................................
% Survival .......Rest of an-m and ----Rest of 40
-
trunk
legs (n
134)
(n = 66)
---Rest
olheadand
-SANS(n
111)
neck (n
921
30 0
1
2
3
4
5
6
7
6
Years aftersurgery
Figure 3. Survlval of patients with stage I melanoma by anatomic site of lesion. BANS = upper back, upperposterior arms,PoSterA or neck, and posterior scalp.
erative years were chosen because the risk of death from melanoma was highest during that period and because the survival rate after 4 years was similar to that expected in the general population when adjusted for age, sex, and calendar year. At 4 years, 349 patients were alive, 53 were dead from melanoma, and 21 were dead from other causes. In addition, 62 patients demonstrated metastatic spread at 4 years. When subgroup survival comparisons, such as men versus women, were made within the categories of thickness, only the estimated percentage of patients surviving at 4 years was plotted for ease of presentation. Results Overall survival rates are shown in Figure 1. Thus, at 4 years, 86 percent of the patients were alive. (The survival curves in the figures have been smoothed out for simplicity and logarithmically plotted so that parallel curves indicate an equivalent risk of death.) Figure 2 demonstrates the 4 year survival rates with respect to thickness of lesions. The 4 year survival rates with respect to lesion site are shown in Figure 3. To provide a more meaningful sample for analysis, patients with lesions less than 1.7 mm in thickness were grouped together and compared with those with other lesion thicknesses. Figure 4 shows survival rates by sex with respect to thickness. The rate in men with lesions 1.70 to 3.65 mm in
Volume 150,october
1995
<
1.69
1.70-3.65 Thickness (mm)
~3.66
Figure 4. Percentage of patlents w/th stage I melanoma survlvlng at 4 years by sex and thickness of lesion.
thickness was somewhat lower than that in women with lesions in that range (p = 0.058). When survival rates were calculated by age, comparing those of patients less than 50 years of age with those of patients 50 years of age or older, no statistically significant differences were found (Figure 5), although the survival rates were lower in the older patients. When 4 year survival rates were examined by morphologic type, patients with nodular melanoma fared somewhat worse when lesions measured 1.70 to 3.65 mm in thickness, although the difference was not statistically significant (p = 0.19). In those with lesions thicker than 3.65 mm, no significant difference in survival rates was detected (Figure 6). Overall survival rates according to level were better for patients with level 2 and 3 disease as opposed to level 4 and 5 disease. Since higher level lesions tend to be thicker, this difference disappeared when levels were compared within thickness groups (Figure 7). When survival was compared by lesion thickness for patients who underwent prophylactic nodal dissection compared with those who did not, no significant differences were found (Figure 8). Note that prophylactic nodal dissection was performed in only 26 percent of the patients (72 of 277) with lesions less than 1.70 mm in thickness, compared with 55 percent of those with thicker lesions (80 of 146 patients). Figure 9 depicts survival
453
Woods
et al
*.
% s”r”l”mg
5.
at 4 years
-. ‘.
‘.
‘-._
-.._
--._-c-.
\\
t
Age <_49 2 50
"
%
n
%
49
% sur"l"lng5. at 4 years
z-50 " %
137 965 140 97.7
56 71.6 51 63.7
16 56.3 23 45.9
I
I
I
< 1.69
170-3.65 Thlckness(mm)
_>3.66
*. Cell Superflclal Nodular
1
Figure 5. Percentage of patients with stage I melanoma surviving at 4 years by age and thickness of lesion.
0
n
%
233
96 6
49 73 7
15 444
933
50 58 2
PO 53 2
17
I s
169
Nonode 205 Elective 72 170-3.65 Thlckness(mm)
Figure 7. Survival of patients with stage /melanoma level and thickness of lesion.
BANS ;4 H&N -
0
T A&L
58 49 96
% 971 98 I 1000 979
< 1.69
”
%
31 23 27 26
660 632 606 829
1.70-3.65
01
~3.66
at 4 years by
n 6 11 10 12
333 318 640 648
I
_>3.66
Thvzkness(mm)
Figure 9. Percentage of patients at 4 years by anatomic site and and legs; BANS = upper back, neck, and posterior scalp; H&N
with stage I melanoma surviving thickness of lesion. A&L = arms upper posterior arms, poster/or = head and neck; T = trunk.
in patients by anatomic site with respect to thickness of the lesions. Here, again, there was not a significant difference between groups, although those with thicker arm and leg and trunk lesions fared somewhat better than those with BANS and non-BANS head and neck lesions. Those patients in the BANS group with lesions 0.76 to 1.69 mm in thickness whose disease was clinically considered to be stage I and underwent prophylactic node dissection with pathologically
454
%
"
I
I
170-365 Thlckness(mm)
2 366
Figure 6. Four year survival in patients morphologic type and thickness.
of nodes n
c 1 69
"
% 979 96 6
00
I
with stage I melanoma by
n % 47 75.3 60 63.0
n % 19 536 20 48.0
I
I
I
< 1.69
170-3.65 Thlckness(mm)
2 366
I
Figure 6. Percentage of patients w/th stage /melanoma survlvlng at 4 years, with and without nodal dissection, with respect to thickness.
positive nodes were compared with the equivalent group of patients with non-BANS head and neck lesions. Fifteen of 35 patients in the BANS group underwent nodal dissection and none had involved nodes, whereas 30 of 85 patients in the non-BANS head and neck group had regional node dissection and 1 had involved nodes. Thus, there was no increased predilection to metastases in the BANS patients with lesions of that thickness. The proportional hazards model of Cox [4] was used to analyze the individual effects of sex, age, level, cell type, treatment of nodes, and site when adjusted for thickness on length of survival in the first 4 years after melanoma was diagnosed. None of these factors was found to significantly affect survival when adjusted for thickness (p > 0.1). Analysis included all of these variables, removing the least important one at each step until all remaining variables were significant at the p < 0.05 level. The only variable included in the final model was thickness. Comments
As has been apparent in studies carried out since the original work of Breslow [5], thickness of the initial lesion is the single most important factor in stage I melanoma. The findings in the present study are consistent with that thesis and our own previous
The American Journal of Surgery
The BANS Concept for Malignant Melanoma
studies [6]; however, agreement is less uniform in other areas. Although there is generally a rough correlation between prognosis and level of penetration [ 71, it was less apparent in our study, probably due to the preponderance of thin lesions. Sixty-five percent of the lesions were less than 1.70 mm thick. In that group only five deaths occurred in the first 4 postoperative years. For lesions 1.70 to 3.65 mm in thickness, there was no significant difference in survival rates between levels 2 and 3 versus levels 4 and 5. As there were only six patients with level 2 and 3 lesions in the 3.66 mm or thicker category, we cannot draw any definite conclusions regarding the influence of level on survival for patients with these lesions. When the effect of prophylactic node dissection was examined, however, we were not able to demonstrate significant benefit regardless of the thickness of lesions. In lesions of intermediate thickness where greater benefit might be expected, no advantage was seen. This is in agreement with a previous study from our institution [8]. Multicenter prospective studies currently under way offer definitive data in this regard. Certainly the data of Balch et al [9] have supported the use of elective node dissection in lesions of intermediate thickness. When the BANS concept was tested, we were unable to show any difference in prognoses for patients with lesions in the BANS area as opposed to the non-BANS head and neck areas, regardless of thickness. In the study of Day et al [I], there were 11 deaths in 67 patients with lesions in the BANS area compared with 1 death in 136 patients with lesions in other areas of the body when the lesions measured 0.76 to 1.69 mm in thickness. In our series there were 2 deaths in 39 patients with lesions greater than 0.76 mm in the BANS area, and no deaths in the 35 patients with lesions 0.76 to 1.69 mm in thickness. Thus, in the 74 BANS patients with lesions from 0 to 1.69 mm, there were only 2 deaths, compared with 3 deaths in the 203 patients with lesions of the same thickness in the remainder of the body. This is not a significant difference. A recent study published by Urist et al [2] indicated a worse prognosis for patients with scalp and neck lesions. They did not, however, differentiate between anterior and posterior neck lesions and did not include posterior upper back and arm lesions, and hence their work is not comparable to ours. The number of patients with posterior scalp lesions alone in our series was too small to provide meaningful data. The influence of ulceration in melanoma was not examined in this study because in many of our patients,
Volume 150, October 1985
those data were not recorded, especially in the earlier part of the study. The preponderance of thin lesions is a weakness of the present study. As expected, in patients with thinner lesions, the survival rate was very good; however, much larger numbers are required to establish significant differences for subset comparisons such as survival rates in patients with lesions in the BANS area compared with the rates in patients with lesions in the other areas of the head and neck. Summary In this study of 427 patients with stage I malignant melanoma seen at the Mayo Clinic between 1973 and 1981, only those patients with complete data with respect to thickness and level of penetration of lesion, morphologic type, and anatomic site were included. Although supporting the widely accepted concept of the prognostic importance of thickness of the lesion, the level of penetration was of much lesser significance in our series, and prophylactic node dissection could not be shown to be of significant benefit. Likewise, the BANS concept proposed by Day et al (11was not corroborated. The reasons for these discrepancies are not fully apparent, although a preponderance of thin and intermediate thickness lesions in our patients may have had some influence on our results. References 1. Day CL, Mihm MC, Sober AJ, et al. Prognostic factors for melanoma patients with lesions 0.76-1.69 mm in thickness. Ann Surg 1982;195:30-4. 2. Urist MM, Balch CM, Soong SJ, et al. Head and neck melanoma in 534 clinical stage I patients. Ann Surg 1984;200:769-75. 3. Kaplan EL, Meier P. Non-parametric estimation from incomplete observations. J Am Stat Assoc 1958;53:457-81. 4. Cox DR. Regression models and life tables. J R Stat Sot 1972;34:187-220. 5. Breslow A. Thickness, cross-sectional areas and depth of invasion in the prognosis of cutaneous melanoma Ann Surg 1970; 172:902. 6. Woods JE. Soule EH, Borkowski JJ. Experience with malignant melanoma of the head and neck. Plast Reconstr Surg 1978;61:64-9. 7. McGovern VJ, Shaw HM, Milton GW, Farago GA. Prognostic significance of the histological features of malignant melanoma. Histopathology 1979;3:385-93. 8. Sim FH, Taylor WF, lvins JC, et al. A prospective randomized study of the efficacy of routine elective lymphadenectomy in management of malignant melanoma: preliminary results. Cancer 1978;41:948-56. 9 Balch CM, Urist MM. Maddox WA, Soong SJ. Melanoma in the southern United States: experience at the University of Alabama in Birmingham. In: Balch CM, Milton GW, eds. Cutaneous melanoma. Philadelphia: JB Lippincott, 1985:397-406.
455
John E. Woods, MD, Rochester, Minnesota William F. Taylor, PhD, Rochester, Minnesota Douglas J. Pritchard, MD, Rochester, Minnesota Franklin H. Sim, MD, Rochester, Minnesota John C. Ivins, MD, Rochester, Minnesota Erik J. Bergstralh, MS, Rochester, Minnesota
In 1982, Day and co-authors [I] analyzed their data on 203 patients with malignant melanoma from 1972 to 1977 who had lesions ranging from 0.76 to 1.69 mm in thickness. They presented the concept that lesions of the upper back, upper posterior arms, posterior neck, and posterior scalp (the BANS areas) had a significantly worse prognosis than lesions of similar thickness located at other sites (16 percent and 0.7 percent, respectively, for the period of study). To our knowledge, this thesis has not been tested and corroborated by other groups, although Urist et al [Z] reported a worse prognosis for patients with lesions on the scalp and neck than for those with facial and ear lesions in a recent report on stage I malignant melanoma of the head and neck. To test the BANS theory, we analyzed data from 1973 to 1981 on patients with stage I malignant disease seen at the Mayo Clinic. Material and Methods There were 648 patients with stage I malignant melanoma seen at our institution from the beginning of 1973 to the end of 1981, but only those whose records had complete information with respect to thickness, level of penetration, and morphologic type, and those seen with their first melanomatous lesion were included. Thickness of the lesions was not known in 136 of the earlier patients. Patients who underwent delayed prophylactic nodal dissection were excluded to provide a clear comparison between those who had immediate wide excision and prophylactic node dissection and those who underwent excision alone. A total of 423 patients were analyzed in this study (191 From the Divisions of Plastic Surgery, Orthopedic Surgery, Biostatistics. and Medical Research Statistics, Mayo Clinic, Rochester, Minnesota. Requests for reprints should be addressed to John E. Woods, MD. Division of Plastic Surgery, Mayo Clinic, Rochester, Minnesota 55905. Presented at the 31st Annual Meeting of the Society of Head and Neck Surgeons, Dorado, Puerto Rico, May 5-8. 1985.
452
women, 45 percent and 232 men, 55 percent). The anatomic distribution of the lesions was as follows: In 111 patients (26 percent), the site was the BANS area; in 92 patients (22 percent), other areas of the head and neck; in 86 patients (20 percent), the trunk; and in the remaining 134 patients (32 percent), the arms and legs. One patient (less than 1 percent of total group) was in the 9 years or younger age group, 9 patients (2 percent) were in the 10 to 19 year age group, 47 patients (11 percent) were in the 20 to 29 year age group, 63 patients (15 percent) were in the 30 to 39 year age group, 89 patients (21 percent) were in the 40 to 49 year age group, 101 patients (24 percent) were in the 50 to 59 year age group, 69 patients (16 percent) were in the 60 to 69 year age group, 35 patients (8 percent) were in the 70 to 79 year age group, 8 patients (2 percent) were in the 80 to 89 year age group, and 1 patient (less than 1 percent of total) was in the 90 years or older age group. Morphologic classification included 39 patients with malignant lentigo or other forms, 297 with superficial spreading, and 87 patients with nodular melanoma. The primary lesions penetrated to level 2 or 3 in 248 patients, whereas 175 patients had lesions that penetrated to levels 4 or 5. Distribution of patients according to thickness of the lesions was as follows: In 157 patients (37 percent), the thickness was 0 to 0.75 mm; in 120 patients (28 percent), 0.76 to 1.69 mm; in 107 patients (25 percent), 1.70 to 3.65 mm; and in 39 patients (9 percent), 3.66 mm or thicker. Wide local excision alone was employed in 271 patients (64 percent), and immediate prophylactic node dissection in addition to wide local excision was carried out in 152 patients (36 percent). Follow-up for patients last known alive ranged from less than 1 year in less than 1 percent to over 10 years in 4 percent, with a median follow-up of 5 years. The method of Kaplan and Meier [3] was used to estimate the percentage of surviving patients. At various times a#er surgery, deaths from other causes were considered withdrawals from the study. The log-rank test was used to compare various subgroups based on survival rates during the 4 years after surgery. The first 4 postop-
The American Journal of Surgewy
The BANS Concept for Malignant Melanoma
90
100 80
1 ‘T
’
-----
:., . ..
-.
‘..,
70
X.,
60 % *"rYI"aI
t
--.--_---
‘\
'. _. ----a______-_-_---'....._ ..... ........._
1 ~~~~~~~~~~
30 ' 0
1
2
3
4
5
6
7
6
0
1
2
3
Figure 1. Patlent survival after surgery tar stage I malignant melanoma.
:““‘” 80
-
70
-
60
-
50
-
4
5
6
7
a
years aftersurgery
years altersurgery
’
..........._-...._
Figure 2. Survival of patients with stage I melanoma by thickness (mm) of primary lesion.
...........................................................
% Survival .......Rest of an-m and ----Rest of 40
-
trunk
legs (n
134)
(n = 66)
---Rest
olheadand
-SANS(n
111)
neck (n
921
30 0
1
2
3
4
5
6
7
6
Years aftersurgery
Figure 3. Survlval of patients with stage I melanoma by anatomic site of lesion. BANS = upper back, upperposterior arms,PoSterA or neck, and posterior scalp.
erative years were chosen because the risk of death from melanoma was highest during that period and because the survival rate after 4 years was similar to that expected in the general population when adjusted for age, sex, and calendar year. At 4 years, 349 patients were alive, 53 were dead from melanoma, and 21 were dead from other causes. In addition, 62 patients demonstrated metastatic spread at 4 years. When subgroup survival comparisons, such as men versus women, were made within the categories of thickness, only the estimated percentage of patients surviving at 4 years was plotted for ease of presentation. Results Overall survival rates are shown in Figure 1. Thus, at 4 years, 86 percent of the patients were alive. (The survival curves in the figures have been smoothed out for simplicity and logarithmically plotted so that parallel curves indicate an equivalent risk of death.) Figure 2 demonstrates the 4 year survival rates with respect to thickness of lesions. The 4 year survival rates with respect to lesion site are shown in Figure 3. To provide a more meaningful sample for analysis, patients with lesions less than 1.7 mm in thickness were grouped together and compared with those with other lesion thicknesses. Figure 4 shows survival rates by sex with respect to thickness. The rate in men with lesions 1.70 to 3.65 mm in
Volume 150,october
1995
<
1.69
1.70-3.65 Thickness (mm)
~3.66
Figure 4. Percentage of patlents w/th stage I melanoma survlvlng at 4 years by sex and thickness of lesion.
thickness was somewhat lower than that in women with lesions in that range (p = 0.058). When survival rates were calculated by age, comparing those of patients less than 50 years of age with those of patients 50 years of age or older, no statistically significant differences were found (Figure 5), although the survival rates were lower in the older patients. When 4 year survival rates were examined by morphologic type, patients with nodular melanoma fared somewhat worse when lesions measured 1.70 to 3.65 mm in thickness, although the difference was not statistically significant (p = 0.19). In those with lesions thicker than 3.65 mm, no significant difference in survival rates was detected (Figure 6). Overall survival rates according to level were better for patients with level 2 and 3 disease as opposed to level 4 and 5 disease. Since higher level lesions tend to be thicker, this difference disappeared when levels were compared within thickness groups (Figure 7). When survival was compared by lesion thickness for patients who underwent prophylactic nodal dissection compared with those who did not, no significant differences were found (Figure 8). Note that prophylactic nodal dissection was performed in only 26 percent of the patients (72 of 277) with lesions less than 1.70 mm in thickness, compared with 55 percent of those with thicker lesions (80 of 146 patients). Figure 9 depicts survival
453
Woods
et al
*.
% s”r”l”mg
5.
at 4 years
-. ‘.
‘.
‘-._
-.._
--._-c-.
\\
t
Age <_49 2 50
"
%
n
%
49
% sur"l"lng5. at 4 years
z-50 " %
137 965 140 97.7
56 71.6 51 63.7
16 56.3 23 45.9
I
I
I
< 1.69
170-3.65 Thlckness(mm)
_>3.66
*. Cell Superflclal Nodular
1
Figure 5. Percentage of patients with stage I melanoma surviving at 4 years by age and thickness of lesion.
0
n
%
233
96 6
49 73 7
15 444
933
50 58 2
PO 53 2
17
I s
169
Nonode 205 Elective 72 170-3.65 Thlckness(mm)
Figure 7. Survival of patients with stage /melanoma level and thickness of lesion.
BANS ;4 H&N -
0
T A&L
58 49 96
% 971 98 I 1000 979
< 1.69
”
%
31 23 27 26
660 632 606 829
1.70-3.65
01
~3.66
at 4 years by
n 6 11 10 12
333 318 640 648
I
_>3.66
Thvzkness(mm)
Figure 9. Percentage of patients at 4 years by anatomic site and and legs; BANS = upper back, neck, and posterior scalp; H&N
with stage I melanoma surviving thickness of lesion. A&L = arms upper posterior arms, poster/or = head and neck; T = trunk.
in patients by anatomic site with respect to thickness of the lesions. Here, again, there was not a significant difference between groups, although those with thicker arm and leg and trunk lesions fared somewhat better than those with BANS and non-BANS head and neck lesions. Those patients in the BANS group with lesions 0.76 to 1.69 mm in thickness whose disease was clinically considered to be stage I and underwent prophylactic node dissection with pathologically
454
%
"
I
I
170-365 Thlckness(mm)
2 366
Figure 6. Four year survival in patients morphologic type and thickness.
of nodes n
c 1 69
"
% 979 96 6
00
I
with stage I melanoma by
n % 47 75.3 60 63.0
n % 19 536 20 48.0
I
I
I
< 1.69
170-3.65 Thlckness(mm)
2 366
I
Figure 6. Percentage of patients w/th stage /melanoma survlvlng at 4 years, with and without nodal dissection, with respect to thickness.
positive nodes were compared with the equivalent group of patients with non-BANS head and neck lesions. Fifteen of 35 patients in the BANS group underwent nodal dissection and none had involved nodes, whereas 30 of 85 patients in the non-BANS head and neck group had regional node dissection and 1 had involved nodes. Thus, there was no increased predilection to metastases in the BANS patients with lesions of that thickness. The proportional hazards model of Cox [4] was used to analyze the individual effects of sex, age, level, cell type, treatment of nodes, and site when adjusted for thickness on length of survival in the first 4 years after melanoma was diagnosed. None of these factors was found to significantly affect survival when adjusted for thickness (p > 0.1). Analysis included all of these variables, removing the least important one at each step until all remaining variables were significant at the p < 0.05 level. The only variable included in the final model was thickness. Comments
As has been apparent in studies carried out since the original work of Breslow [5], thickness of the initial lesion is the single most important factor in stage I melanoma. The findings in the present study are consistent with that thesis and our own previous
The American Journal of Surgery
The BANS Concept for Malignant Melanoma
studies [6]; however, agreement is less uniform in other areas. Although there is generally a rough correlation between prognosis and level of penetration [ 71, it was less apparent in our study, probably due to the preponderance of thin lesions. Sixty-five percent of the lesions were less than 1.70 mm thick. In that group only five deaths occurred in the first 4 postoperative years. For lesions 1.70 to 3.65 mm in thickness, there was no significant difference in survival rates between levels 2 and 3 versus levels 4 and 5. As there were only six patients with level 2 and 3 lesions in the 3.66 mm or thicker category, we cannot draw any definite conclusions regarding the influence of level on survival for patients with these lesions. When the effect of prophylactic node dissection was examined, however, we were not able to demonstrate significant benefit regardless of the thickness of lesions. In lesions of intermediate thickness where greater benefit might be expected, no advantage was seen. This is in agreement with a previous study from our institution [8]. Multicenter prospective studies currently under way offer definitive data in this regard. Certainly the data of Balch et al [9] have supported the use of elective node dissection in lesions of intermediate thickness. When the BANS concept was tested, we were unable to show any difference in prognoses for patients with lesions in the BANS area as opposed to the non-BANS head and neck areas, regardless of thickness. In the study of Day et al [I], there were 11 deaths in 67 patients with lesions in the BANS area compared with 1 death in 136 patients with lesions in other areas of the body when the lesions measured 0.76 to 1.69 mm in thickness. In our series there were 2 deaths in 39 patients with lesions greater than 0.76 mm in the BANS area, and no deaths in the 35 patients with lesions 0.76 to 1.69 mm in thickness. Thus, in the 74 BANS patients with lesions from 0 to 1.69 mm, there were only 2 deaths, compared with 3 deaths in the 203 patients with lesions of the same thickness in the remainder of the body. This is not a significant difference. A recent study published by Urist et al [2] indicated a worse prognosis for patients with scalp and neck lesions. They did not, however, differentiate between anterior and posterior neck lesions and did not include posterior upper back and arm lesions, and hence their work is not comparable to ours. The number of patients with posterior scalp lesions alone in our series was too small to provide meaningful data. The influence of ulceration in melanoma was not examined in this study because in many of our patients,
Volume 150, October 1985
those data were not recorded, especially in the earlier part of the study. The preponderance of thin lesions is a weakness of the present study. As expected, in patients with thinner lesions, the survival rate was very good; however, much larger numbers are required to establish significant differences for subset comparisons such as survival rates in patients with lesions in the BANS area compared with the rates in patients with lesions in the other areas of the head and neck. Summary In this study of 427 patients with stage I malignant melanoma seen at the Mayo Clinic between 1973 and 1981, only those patients with complete data with respect to thickness and level of penetration of lesion, morphologic type, and anatomic site were included. Although supporting the widely accepted concept of the prognostic importance of thickness of the lesion, the level of penetration was of much lesser significance in our series, and prophylactic node dissection could not be shown to be of significant benefit. Likewise, the BANS concept proposed by Day et al (11was not corroborated. The reasons for these discrepancies are not fully apparent, although a preponderance of thin and intermediate thickness lesions in our patients may have had some influence on our results. References 1. Day CL, Mihm MC, Sober AJ, et al. Prognostic factors for melanoma patients with lesions 0.76-1.69 mm in thickness. Ann Surg 1982;195:30-4. 2. Urist MM, Balch CM, Soong SJ, et al. Head and neck melanoma in 534 clinical stage I patients. Ann Surg 1984;200:769-75. 3. Kaplan EL, Meier P. Non-parametric estimation from incomplete observations. J Am Stat Assoc 1958;53:457-81. 4. Cox DR. Regression models and life tables. J R Stat Sot 1972;34:187-220. 5. Breslow A. Thickness, cross-sectional areas and depth of invasion in the prognosis of cutaneous melanoma Ann Surg 1970; 172:902. 6. Woods JE. Soule EH, Borkowski JJ. Experience with malignant melanoma of the head and neck. Plast Reconstr Surg 1978;61:64-9. 7. McGovern VJ, Shaw HM, Milton GW, Farago GA. Prognostic significance of the histological features of malignant melanoma. Histopathology 1979;3:385-93. 8. Sim FH, Taylor WF, lvins JC, et al. A prospective randomized study of the efficacy of routine elective lymphadenectomy in management of malignant melanoma: preliminary results. Cancer 1978;41:948-56. 9 Balch CM, Urist MM. Maddox WA, Soong SJ. Melanoma in the southern United States: experience at the University of Alabama in Birmingham. In: Balch CM, Milton GW, eds. Cutaneous melanoma. Philadelphia: JB Lippincott, 1985:397-406.
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