The influence of patient characteristics on the appropriateness of surgical treatment for breast cancer patients

Annals of Oncology 4: 133-140, 1993. © 1993 Kluwer Academic Publishers. Printed in the Netherlands.

Original article The influence of patient characteristics on the appropriateness of surgical treatment for breast cancer patients A. Nicolucci,1 F. Mainini,2 A. Penna,2 N. Scorpiglione,1 R. Grilli,2 C. Angiolini,2 E. Mari,1 P. Zola 3 & A. Liberati2 A Study carried out by the Progetto Oncologia Femminile 'Unita' di Epidemiologia Clmica, Consorzio Mario Negri Sud, S. Maria Imbaro (CH) Italy; 2Laboratorio di Epidemiologia Clinica, Istituto Mario Negri, Milan Italy; -1 Istituto di Ostetricia e Cinecologia, Universitd di Torino Italy (See Appendix 1 for list of Scientific Commitee)

small tumors (i.e., <2 cm) was under utilized. Chronological age influenced physicians' behaviour: elderly patients were Background: Within the framework of a multi-annual edu- more likely to have a less intensive diagnostic work-up and cational intervention sponsored by the Ministry of Health less appropriate surgical treatment (with more frequent perand regional health authorities, patterns of the care delivered formance of an unnecessary radical operation and a less freto breast cancer patients in Italian general hospitals were quent utilization of limited surgery), independently of their monitored in order to identify areas of practice whose quality overall health status. The presence of one or more co-existent diseases was associated with a failure to undergo axillary was in need of improvement. Design: Information on the diagnostic and therapeutic clearance and with a lower utilization of conservative surgery procedures in 63 general hospitals in eight Italian regions independently of age. performed in 1724 consecutive breast cancer patients were Conclusion: In accord with others, this study confirms the retrospectively gathered from medical records. Quality of existence of a clinically important effect of patient age on care was assessed by a diagnostic and therapeutic score diagnostic and therapeutic behaviour and the use of unnecesbased on the observed degree of compliance with previously sarily radical surgical procedures. The paper discusses the established courses of action. implications of these findings for the next stage of the educaResults: The median value of the overall diagnostic and tional project, in which practice guidelines will be developed staging score was 60%. About one-third of surgical opera- and implemented to improve the quality of care for breast tions (38%) were inappropriate: one-fourth (24%) of patients cancer patients. with stage I-II disease had unnecessarily radical surgery (i.e., Halsted mastectomy), and limited surgery in patients with Key words: breast neoplasm, human, quality of health care Summary

Introduction A few studies have shown wide variation in the quality of care for breast cancer patients treated outside specialized institutions [1, 2]. While some of the disparity can be accounted for by differences in structural and organizational settings [3|, the importance of knowledge, attitudes and beliefs of physicians in influencing medical decisions has also been pointed out [4, 5]. Among factors affecting decision-making, an important role seems to be played by patient age. Chronologic age is associated with unfavourable characteristics such as the presence of comorbid conditions, low tolerance for treatments and poorer prognosis. In addition, doctors seem to assume that cosmetic results of surgical treatments are of lesser importance when patients are older. Thus, elderly patients have been shown to receive, on the basis of chronologic age alone, suboptimal treatments [6, 7). Indeed, other factors, such as stage of the tumor, performance status and coexistent diseases, influence medical decision-making, but the separate

effects of these factors on cancer diagnosis, staging and treatment have seldom been distinguished from one another. Within the framework of a multiannual educational intervention aimed at improving standards of care by the production and dissemination of treatment guidelines [8], a retrospective study, based on chart review, was performed of the impact of patient characteristics (age, co-morbidity and stage of disease) on patterns of diagnostic and surgical treatment for breast cancer. Patients and methods The study was conducted in 63 hospitals, selected within 8 Italian regions from the three main geographic areas (Northern, Central, and Southern Italy) and sampled in such a way as to assure that different organizational levels of care were represented. Data were retrospectively collected from medical records by a trained physician for each region and recorded on ad-hoc forms. These listed: a) diagnostic and staging examinations; b) the presence and extent of co-existent diseases (comorbidity); c) type of surgery; d) disease stage classified according to the TNM system in its 1987 version [9|.

134 Assessment of appropriateness of care Patient care was assessed using the criteria map technique [10| that summarizes in one score the quality of diagnosis and therapy strategies. Criteria maps are organized in a branching logic format that establishes the appropriate disease management pathway for each patient on the basis of clinical, pathology and laboratory findings. Appropriateness is based upon those exams/procedures that refer to specific symptoms and to the stage of disease. Criteria maps incorporate only widely accepted practice standards, based on acceptable scientific evidence or expert majority opinion where evidence conflicts or is insufficient. The maps used in this study were drafted by the Coordinating Center, reviewed by members of the Scientific Committee and modified according to their suggestions (see Appendix 2). The maps were divided into 2 parts: the first projects diagnostic and staging examinations according to specific types of patient presentation, and the second lists the surgical procedures appropriate for the different categories of patients. Each case receives a separate score for the two parts. The score is then computed as a weighted proportion of the number of appropriate criteria fulfilled, and range from 0 to 100. A procedure is considered 'performed' if reported in the medical record either as performed or as requested. The proportion of requested over performed exams had a different distribution for different exams, ranging from 20% for mammograms to 5% for liver and bone scan, without evidence of differences by patient age. Disease stage is classified as early, locally advanced or metastatic on the basis of the value of pathologic TNM; in the absence of information on the pathologic size of the primary or nodal status, patients were classified as having an early stage provided they were not T4 and/or N2 in the clinical TNM classification.

Patient variables included in the analysis were the following: age (<50, 50-70, >70); comorbidity (C.I. 0-1, C.I. 2-3); stage of disease (early - T l - 3 N0-1 M0; advanced - T4 any N or T l - 3 N2 M0; metastatic - T l - 4 NO-3 Ml). In addition, imbalances in the hospital variables were accounted for in the analysis: hospital size (classified into 3 groups according to number of beds: <200, 200500, >500), number of breast operations per year (<20, 21-50, >50), level of specialization (hospitals without oncology departments, hospitals with either in-patient or out-patient radiotherapy or oncology departments), university affiliation (yes/no). Five different models were run with diagnostic score (<53/>53), appropriateness of surgery (appropriate/not appropriate), utilization of quadrantectomy in patients with primary tumor <2cm (yes/ no), inappropriate Halsted mastectomy (yes/no) and axillary dissection (yes/no) as dependent variables. Predictor variables were: age (reference category (RC) - <50 years), C.I. (RC - 0-1), stage of disease (RC - early), (patient-related variables); hospital size (RC — <200 beds), number of breast operations per year (RC - <20/year); specialization (RC — hospitals without oncologic organization), academic affiliation (RC - no). All regression models, except for the second - in which (254, 15%) have to be excluded because of the lack of precise information on the pathologic size of the primary and/or nodal status - included 99% patients. The significance of the linear trend was assessed using the Mantel-Haenzel test 1111.

Results General characteristics of the sample

A total of 1724 cases of breast adenocarcinoma diagnosed during the period 1988-1989 in 63 hospitals (median number of patients per hospital •=• 43, range Patients' general health status was measured using a modified ver- 1-103) were sampled. Table 1 shows the patients' gension of the Comorbity Index (C.I.) already used in other studies [6|. eral characteristics. It evaluates diseases other than breast cancer that may affect cancer Co-morbidity was reported for 426 patients (25%); management. The index has two components: the Individual Disease Value (IDV) and the Functional Status (FS). The former describes impairment of one or more of 12 functional areas listed the severity and the presence of specific complications for each dis- in the comorbidity index occurred in 142 patients. ease on a scale ranging from 0 (completely recovered disease or not Table 2 shows its distribution in the study population. actually treated) to 3 (life-threatening disease). For example, for a Elderly patients were more likely to have locally adpatient suffering from diabetes mellitus a score equal to 0 refers to a chemical diabetes only, a score of 1 refers to a diabetes controlled by vanced disease at presentation (12%, 11% and 22% for medications, insulin or diet, a score of 2 refers to a diabetes not con- women aged <50, 50-70 and >70 years, respectively) trolled or with neuropathy, nephropathy, retinopathy, acidosis, etc., and more often had moderate-severe comorbid condiAssessment of coexistent diseases

and a score of 3 refers to a diabetic coma, shock, severe heart disease, or end-stage renal disease. The FS evaluates the impact of all conditions, diagnosed or not, on the patients current health status. The measure of FS is derived from signs and symptoms from 12 system categories (circulation, respiration, neurological, mental status, urinary, intestinal, feeding, ambulation, transfer, vision, hearing and speech). Each area is given a score ranging from 0 (no impairment) to 2 (severe impairment). IDV and FS scores have been combined by means of specific algorithms into one index ranging from 0 (no comorbidity) to 2 (severe conditions of co-morbidity or severe impairment of functional status).

Statistical analysis The diagnostic score was divided to separate patients with a value lower or equal to the 25th percentile (i.e. < 53%) from all the others. Surgical appropriateness was analyzed as dichotomous variable (appropriate - non-appropriate). To assure simultaneous control for the potentially confounding effects of different variables, a series of multivariate analyses was carried out through logistic regression entering variables in a forward stepwise fashion.

Table I. Selected characteristics of 1724 cases of breast cancer enrolled in the study. Age Median Range Menopausal status Premenopausal Postmenopausar1 Not evaluable

61 yrs 17-89yrs 366(21%) 1274 (74%)

84 (5%)

Pathologic nodal status Node-negative Node-positive Not evaluable

722 (42%) 706(41%) 296(17%)

Pathologic disease stage Early Locally-advanced Metastatic

1432(83%) 263(15%) 29 (2%)

" Includes perimenopausal patients.

135

groups appeared to be due to a consistently lower execution of diagnostic examinations in older patients (mammogram: 76% vs. 74% vs. 68%; FNA: 27% vs. 23% vs. 21%; pre-surgical biopsy: 16% vs. 10% vs. 9% for patients < 50, 50-70 and > 70 yrs, respectively). While no difference related to age emerged in the rate of execution of staging examinations (chest x-ray, liver and bone examination), more than six axillary nodes were removed less often in older patients than in younger ones: 83% vs. 78% vs. 57% for patients <50, 50-70 and >70 yrs, respectively. Measurement of oestrogen receptors was also negatively associated with age (55% vs. 46% vs. 34% ) (Table 4). Finally, pathologic nodal status and pathologic staging were less frequently reported in older patients (nodal status: 89% vs. 86% vs. 70%; pathologic staging: 67%, 63% and 57%).

Table 2. Distribution of 1724 breast cancer patients according to the comorbidity index (C.I.).

.0

n.

(%)

1298

(75) (17)

296 58 64

.2 .3-4 . N.V.

(3) (4)

tions (C.I. •= 2-3) (3%, 5% and 15% for women aged < 50, 50-70 and > 70 years, respectively). Diagnosis and staging

Table 3 shows the percentage of patients with scores <53% according to age, comorbidity index and stage of disease. The percentage of cases with lower diagnostic scores was higher for patients older than 70 (20%, 24% and 32% for patients aged <50, 50-70 and >70 years, respectively). The multivariate analysis shows that even after adjustment for other potential confounders, elderly patients still showed an almost two-fold probability (ORML - 1.7, 95% CI = 1.3-2.2; p < 0.01) of having a score lower than 53 compared to younger patients. The quality of diagnosis and staging did not seem to be related to comorbidity or disease stage. Differences in the thoroughness of diagnosis among age

Surgical patterns and appropriateness

Of 1724 patients, 1680 underwent surgical operation. Table 5 lists the different types of surgery performed. Table 3 shows the percentage of appropriate surgical operations according to age, comorbidity and disease stage. Of 1429 evaluable patients with non-metastatic disease at diagnosis, 541 (38%) had operations which were classified as inappropriate for the following reasons:

Table 3. Appropriatenes of diagnostic work-up and of surgical treatment according to age, co-morbidity and stage of disease. Surgical treatment

Diagnostic score <53

Age <50

50-70 >7()

Inappropriate

Appropriate

(80) (76) (68)

n. 130 251 160

(33) (36) (46)

n. 259 442 190

(67) (64) (54)

(74) (82)

618 42

(38) (42)

829 58

(62) (58)

(75) (75)

409 132

(34) (59)

801 90

(66) (41)

>53

n. 91 197 140

(20) (24) (32)

n. 365 617 292

405 22

(26) (18)

1 168

358 65

(25) (25)

1058

(%)

(%)

(%)

(%)

Comorbidity index 0-1 2-3

Stage Early Advanced

99

192

Total no. of patients in the different groupings does not always correspond to the number of subjects enrolled because information is missing in specific categories. Table 4. Frequency of performance of diagnostic, staging and pathology assessment according to age among 1724 breast cancer patients. Diagnostic tests (% execution)

Age <50 50-70 >70

nc 464 824 436

Pathology assessment (% execution)

Staging examinations (% execution)

Mammography

FNA"

Pre-surg. biopsy

Liver examination

Chest x-ray

Skeletal examination

Axillaryb nodes

Oestrogen receptor assay

Histotype

78' 81' 74'

22' 19' 26'

16d 10d

58 57 57

94 94 93

63 63 61

83' 78' 57'

55' 46' 34'

97 97 96

' Fine-needle aspiration;

b

9d

More than six examined; X 2 for linear trend:' p < 0.05; d p < 0 . 0 1 ; 'p < 0.001.

136 Table 5. Frequency of different types of surgery among 1680* breast cancer patients. Types of surgery

n.

Halsted mastectomy Patey mastectomy Madden mastectomy Quadrantectomy/tumorectomy + axillary dissection Simple mastectomy Quadrantectomy/tumorectomy without axillary dissection Other

408 529 286 300 76

(24) (31) (17) (18) (4)

50 31

(3) (2)

44 patients did not undergo any surgery.

Halsted mastectomy in tumors not fixed to the underlying pectoral muscle (n — 357; 66%); surgery without axillary clearance (n - 79; 15%); quadrantectomy or lumpectomy in tumors larger than 2 cm (n - 69; 13%); mastectomy according to Madden in locally advanced tumors (n - 24; 4%); mastectomy according to Patey in tumors fixed to underlying pectoral muscle (n = 6; 1%), and other (n = 6; 1%). Surgical appropriateness decreased with age (67% vs. 64% vs. 54% for patients <50, 5070 and >70 years old, respectively; x2 for lincar lrcnd = 13.2, p < 0.01). These results were also confirmed at multivariate analysis. After controlling for potential imbalances in patient and hospital characteristics, women older than 70 still had a 70% greater probability of undergoing an inappropriate operation than younger patients (i.e. <50) (ORML = 1.7, 95% CI - 1.3-2.2; p > 0.01). Surgical appropriateness was also negatively associated with pathologic stage: at multivariate analysis women with locally advanced disease had an almost three-fold probability of inappropriate surgery (ORML = 2.8, 95% CI - 2.1-3.9; p < 0.01). Correlates of appropriateness by type of surgery were also analyzed. Compared to younger patients, women 50 to 70 years old were more likely to have inappropriate Halsted radical mastectomies (ORML - 1.8, 95% CI = 1.4-2.3; p < 0.01). Greater utilization of this type of unnecessary radical surgery among older women was evident even in patients with small primary tumors: its frequency was 9% in patients younger than 50, 13% in those 50-70 and, finally, 21% among women 70 years or older (Table 6). Use of Halsted mastectomy was also positively associated to stage of disease: at multivariate analysis patients with locally advanced disease had a two-fold probability of having this type of surgery (ORML = 2.0, 95% CI - 1.4-2.8; p < 0.01). Co-morbidity was not related to unnecessary radical mastectomy.

severe co-morbidity only 8% of eligible patients had the procedure compared to 39% of women with no or minimal concomitant disease (ORML = 5.7, 95% CI -=• 1.3-25 p = 0.02). Finally, both age and comorbidity were independent predictors of the failure to receive a thorough axillary clearance. At multivariate analysis older patients had a five-fold increased chance of an incomplete nodal dissection (ORML = 5.3, 95% CI = 3.5-7.8, p < 0.01), while patients with severe comorbid conditions were twice as likely to undergo the same incomplete diagnostic process (ORML - 1.9, 95% CI = 1.1-3.4, p = 0.02). Table 6. Frequency (percent) of different types of surgery among 410 breast cancer patients with primary tumors <2cm according to their age. Age

No. of patients

Halsted

Patey/ Madden

Quadr/ tumorect + axillary dissection

Other"

<50

134 213 63

9% 13% 21%

42% 44% 43%

44% 38% 25%

5% 4% 10%

50-70 <70

' Tumorectomy/quadrantectomy without axillary dissection, simple mastectomy.

Discussion

In keeping with the few studies thus far carried out, our data suggest that age is an important factor affecting the quality of diagnostic and therapeutic procedures in breast cancer patients. Furthermore, this study indicates that the effect of age is independent of other patient (i.e. co-morbidity and disease stage) and structural characteristics and that indeed women aged more than 70 years are more likely to be given fewer diagnostic tests and to receive inappropriate surgery. With respect to diagnosis, it may be argued that a less intensive work-up is justified because a solid lump is more likely to be a cancer in an older than in a younger woman. Even though this view is certainly rooted among clinicians, we are unaware of any official recommendation supporting this practice. Furthermore, at least part of the limited utilization of some diagnostic procedures may either reflect poor quality of medical records or the fact that they were performed before the index hospitalization and not subsequently Quadrantectomy was performed less frequently in entered into the medical charts. Whatever the underolder patients (42%, 39% and 24%, respectively; x2 for lying reason, it is worth mentioning that we found no linear trend = 5.7 p — 0.016) and this held true also at clear evidence in our study that completeness of data multivariate analysis, indicating that older women had differed among age groups, as the uniform distribution a double risk of not receiving limited surgery (ORML -= and availability of information on staging procedure illustrates (see Table 4). 2.0, 95% CI = 1.1-3.7; p = 0.02). Substantially 'harder' is the information provided by The presence of one or more co-existent disease(s) was negatively associated with the likelihood of under- this study relative to the utilization of surgical progoing a conservative procedure: among patients with cedures. The limited frequency of conservative surgery

137

and even more the still common application of the Halsted mastectomy in elderly patients with small primary tumors suggest limited regard for functional consequences of the treatment and for cosmetic results associated with patient age. Previous studies on doctors' behavior with respect to information-sharing with breast cancer patients in Italy [12, 13] have shown that most patients are not told they have cancer nor are they involved in treatment decision-making. This makes it unlikely that preference by women for a radical operation was at the root of what we observed. Assessment of nodal status and, according to some, total axillary clearance, are procedures with both diagnostic and therapeutic value. Indeed, there is still controversy as to whether axillary clearance or a 'watchand-wait' policy, with surgery or radiotherapy kept in reserve, is better for the patient or if they are equally acceptable [14-16]. The importance of assessing nodal status to guide the choice of adjuvant treatment is also a concept under revision due to the recent evidence suggesting the value of also treating node-negative women [17, 18]. Our findings, however, should be judged in light of what was known and recommended in 1988 (no adjuvant therapy was then indicated in node-negative patients [19]) and even today the attitude still prevails that these patients should not be treated. Our data also corroborate the evidence that co-morbidity is an important factor to be considered when trying to understand medical decision-making [6]. In our study women with moderate to severe concomitant diseases were less likely to have conservative surgery, probably because of the anticipated burden of radiotherapy treatment. Co-morbidity was also associated with an increased risk of a surgical procedure without axillary dissection. It may be inferred that surgeons probably balanced out the need of a thorough staging against the increased surgical risk and the idea that aggressive adjuvant treatments (i.e. chemotherapy) would not have been effective in these patients anyway. On the other hand, adequate local control in the absence of nodal dissection can be obtained only with radiotherapy to the axilla. This treatment may be poorly tolerated by elderly patients and can be responsible for additional burden and morbidity. Finally, it is worth noting that despite the lack of any obvious scientific justification for more extensive surgery in patients with T4 or N2 tumors, we also found that the use of Halsted mastectomy was more common when there was locally advanced disease. Some potential limitations of this study should be discussed. The first stems from the source of the data retrieved. As with all retrospective medical audits based on patients' chart data, completeness depends heavily upon the quality of reporting and record keeping. While this is true and may have affected our results to some extent, especially with reference to diagnostic examinations, it is important to bear in mind that our appropriateness assessment was restricted to proce-

dures fully relevant to patient outcome and more likely to be reported in medical records, if actually performed. In the analysis of diagnostic and staging pattern, on the other hand, we considered inappropriate only cases falling below the lowest 25% of the distribution, representing patients for whom the number of procedures performed was substantially less than the average. Another potential limitation of this study has to do with the reliability and validity of data collected from medical records. The validity of all data reported in patients' charts was taken at face value with the exception of the assignment of disease stage whose consistency was a posteriori checked by the coordinating center before data analysis was carried out. As for reliability, an a-posteriori check was done on approximately 20% of charts showing that the error rate was within acceptable boundaries. Specifically, it went from 3% for information related to surgical treatment to 16% for data relative to omission of information on the presence/ absence of a coexisting disease or an active treatment for its control.

Conclusions This study confirms the existence of a statistically significant and clinically important independent effect of patient age on diagnostic and therapeutic behavior. Given the frequency of the disease in this age population and the fact that our findings cannot be attributed to a worse general health status among elderly patients we believe that specific efforts should be made to change this 'age-bias', so that doctors will decide on the basis of the chronologic rather than the physiologic age of patients. Our results, obtained within the framework of an educational project, are currently being used to produce regional guidelines using an explicit group technique [20] for the surgical management of breast cancer, among other disorders. Recommendations will be prepared taking into account the role of age, stage and co-morbidity, in order to render physician attitudes explicit and to incorporate factors relevant to the medical decision-making process [21]. Aside from educational interventions targeted at physicians, there is little doubt that efforts to improve communication with patients and to increase public awareness of different treatment options for breast cancer is a timely and important measure to be taken, especially in many European countries where current practice is still dominated by a quite different attitude. Acknowledgments

Oncologia Femminile is an Italian Ministry of Healthsponsored demonstration project testing the feasibility

138 and yield of educational interventions aimed at improving the quality and appropriateness of care in the area of gynecologic oncology. The project is financially supported by a national research grant from the "Fondo Sanitario Nazionale relativo alle spese vincolate". Dr. Scorpiglione is a fellow of the Centro di Formazione e Studi per il Mezzogiorno-Formez-(Progetto Speciale "Ricerca Scientifica e Applicata nel Mezzogiorno").

Appendix 1 Scientific Committee: Brignone G., Confalonieri C, De Lena M., Di Vito F., Iacobelli S., Lombardo R., Pecorelli S., Perraro E, Tonato M. (Regional Scientific Coordinators); Boccardo E, Bruzzi P., Calabresi E, Canaletti R., Di Giulio P., Mangioni C, Martino G., Rosselli Del Turco M_, Saccozzi R., Sinistrero G., Sismondi P., Taroni E, Tumolo E, Turolla E., Villani C, Zuccali R. Appendix 2 Criteria mapping relative to diagnosis, staging, surgical treatment and pathology findings for patients with newly diagnosed breast cancer. Empty squares indicate different clinical situations; shadowed squares indicate procedures to be performed and used to compute the overall scores.

DIAGNOSIS Reason(s) for hospital admission Breast lump Skin alterations Alterations of the nipple

Clinical examination

Other

Nipple discharge Nipple eczema

Mammogram

:H

If dnctmge or eczema

Cytologic evaluation

m\

Abnormal mammogram

Positive for cancer Suspicious for cancer

Positive FNA* Negative

or

Insufficient specimen

Biopsy

Positive

* FNA — Fine needle aspiration

Staging work-up

139 STAGING

PATHOLOGICAL FINDINGS Any positive exam

Tumor size

All negative

Axillary nodes removed > 6 Positive Negative

Positive

Skin changes without distant metastases

W

Biopsy or FNA

-

Number of nodes examined Estrogen receptor assay Information on skin and muscle fixation

Negative

Positive

Abnormal neurological status

Head CT scan Negaiive

References Any posinve

Management of metastaric disease

Ail negative

Suigical treatment

SURGICAL TREATMENT Modified radical mastectomy according to Patey or Madden T, No.,

With fixation to the pectoral muscle Quadrameciomy with axillary dissection Radical mastectomy [ | according to Halsted j

T2.3 No.,

Widi fixation to the pectoral muscle

Ves

Radical mastectomy according to Halsted

No r Modified radical mastectomy according to Paiey or Madden

T<0 Nj Operable

With fixation to the pea oral muscle

,es

Radical mastectomy according to Halsted

%n, •-

No r Modified radical mastectomy according to Paiey or Madden

Surgical treatment controindicaied because of comorbidity

T4 any N and N2 any T Not operable

Raliotherapy and/or endocrine therapy

«*M

Biopsy for assessment of receptor status if not previously done

1. G.I.V.I.O. Diagnosis and first-line treatment of breast cancer in Italian general hospitals. Tumori 1986; 72: 273-83. 2. Lazovich D, White E, Thomas DB et al. Underutilization of breast-conserving surgery and radiation therapy among women with stage I or II breast cancer. JAM A 1991; 266: 3433-8. 3. Hand R, Sener S, Imperato J et al. Hospital variables associated with quality of care for breast cancer patients. JAMA 1991; 266: 3429-32. 4. Liberati A, Apolone G, Nicolucci A et al. The role of attitudes, beliefs and personal characteristics of italian physicians in the surgical treatment of early breast cancer. Am J Publ Health 1991;81: 38-42. 5. Deber RB, Thompson GG. Who still prefers aggressive surgery for breast cancer? Implications for the clinical applications of clinical trials. Ann Intern Med 1987; 147: 1543-7. 6. Greenfield S, Blanco DM, Elashoff RM et al. Patterns of care related to age of breast cancer patients. JAMA 1987; 257: 2766-70. 7. Samet J, Hunt WC, Key C et al. Choice of cancer therapy varies with age of patient. JAMA 196; 255: 3385-90. 8. Progetto Oncologia Femminile. Protocollo di studio. Fase sperimentale. Milano, 1991. 9. TNM Classification of Malignant Tumours. International Union Against Cancer. Geneva, 1987. 10. Greenfield S, Lewis CE, Kaplan SH et al. Peer review by criteria mapping: Criteria for diabetes mellitus. Ann Intern Med 1975; 83: 761-70. 11. Mantel H, Haenszel W. Statistical aspects of the analysis of data from retrospective studies of disease. J Natl Cancer Inst 1959; 22: 719-48. 12. Mosconi P, Meyerowitz BE, Liberati MC et al. Disclosure of breast cancer diagnosis: Patient and physician reports. Ann Oncol 1991; 2: 273-80. 13. G.I.V.I.O. Survey of treatment of primary breast cancer in Italy. BrJ Cancer 1988; 57:630-4. 14. Cabanes PA, Salmon RJ, Vilcoq JR et al. Value of axillary dissection in addition to lumpectomy and radiotherapy in early breast cancer. Lancet 1992; 1: 1245-8. 15. Fentiman IS, Mansell RE. The axilla: Not a non-go zone. Lancet 1991; 1: 221-3. 16. Sacks NPM, Barr LC, Allan SM et al. For debate: The role of axillary dissection in operable breast cancer. 1992; 1:41 -9. 17. Early Breast Cancer Trialists Collaborative Groups. Systemic

140 treatment of early breast cancer by hormonal, cytotoxic or immune therapy. Lancet 1992; 339: 1-15. 18. Early Breast Cancer Trialists Collaborative Groups. Systemic treatment of early breast cancer by hormonal, cytotoxic or immune therapy. Lancet 1992, 339:71 -85. 19. Forza Operativa Nazionale sul Carcinoma della Mammella I tumori della mammella. Protocollo di diagnosi, trattamento, riabihtazione e cure palliative. Milano, Settembre 1989. 20. Park RE, Fink A, Brook RH et al. Physician ratings of appropriate indications for three procedures: Theoretical indications vs indications used in practice. Am J Public Health 1989; 79: 445-7.

21. Kosecoff J, Chassin MR, Fink A et al. Obtaining clinical data on the appropriateness of medical care in community practice. JAMA 1987; 258: 2538-42. Received 30 June 1992; accepted 29 September 1992. Correspondence to: Alessandro Liberati, M.D. Progetto "Oncologia Femminile" Coordinating Center Laboratorio di Epidemiologia Clinica Istituto Mario Negn Via Eritrea 62 20157 Milan, Italy