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Primary oral squamous cell carcinoma: A review of 92 cases
R.A.
955
ORD
J Oral Maxillofac 54:9%x, 1996
Surg
Discussion Primary
Oral Squamous Cell Carcinoma: A Review of 92 Cases
R.A. Ord, ivfD, DOS, FRCS University of Maryland Cancer Center,
Baltimore,
Maryland
The authors’ definition of oral cancer as a malignant disease affecting the “oral and oropharyngeal mucosa and the tongue” is not the universally accepted definition.’ Oropharyngeal cancers (ie, lesions of the anterior pillar, tonsil, soft palate, and base of tongue) appear to have a different biological behavior than oral cancers and are generally more radiation sensitive. The authors also exclude lip cancer, which is usually defined as an oral cavity cancer.’ The data from this series reflect similar findings of other authors regarding the epidemiology of oral cancer, except for the predominance of early cancers (stage I and II) in which 73% were documented. It is tempting to conclude that referrals to an oral and maxillofacial surgery unit would come primarily from dentists who are more expert at oral examination and detecting early disease. However, in my personal 5-year series of 159 patients with oral epidermoid carcinoma treated at the Oral and Maxillofacial Surgery Unit at the University of Maryland only 48% were stage I or II, despite a virtually 100% dental referral pattern. The authors’ improved survival rate is obviously related to the high percentage of early disease and the fact that only 7 (8%) of the patients had histologically proven nodal disease. Although it is true that the survival rate for oral cancer has changed little in the last 30 years, there has been a considerable change in the way these patients die. I disagree with the authors’ emphasis on locoregional disease to the exclusion of distant metastases and second primary cancers in the upper aerodigestive tract. Their contention that 80% of patient’s dying of oral cancer have locoregional disease is supported by a reference from 1960, and much has changed in the last 36 years. Indeed many recent papers have reported an 80% local and regional control.’ Although local recurrence and control in the neck continue to be a significant problem for stage III and IV patients, an increasing number of these patients succumb to distant rnetastases or second primary cancers. The authors’ short follow-up of 2-year survival is the reason that these problems did not become more evident in their series. The vast majority of local recurrences occur within 3 years of surgery (most in the first year, less in the second year, and the remainder in the third year) and, therefore, a 2-year survival follow-up will identify most persistent or locally recurrent disease. However, it is generally accepted that there is a 6% per year risk of developing a second primary cancer in the upper aerodigestive tract. This risk remains constant per year and does not lessen with time. Therefore, the longer the patient survives the initial primary, the greater the cumulative risk of a second cancer. As the majority of stage III and IV patients tend to die within
the first 3 years, and this risk is greatest for those patient’s with stage I and II disease who were “cured.” This explains the current interest in chemoprevention with retinoids3 Although the authors unsurprisingly show decreasing survival rates with increasing TNM stage, they were unable to show the importance of histological grading. Other authorities have shown the increased ability of the TNM system to stage tumors more accurately when histological grade (P) and site (S) are incorporated, (STNMP classification).4 More recently, head and neck surgeons have focused on tumor thickness as a prognostic indicator.5,6 This appears to be extremely valuable in predicting risk for nodal metastasis, and any further review by the authors of their oral cancer patients would be enhanced by including details of this variable. Lastly, only 28 of the reported patients (30%) underwent neck dissection, although 60 (62%), had T2 primary tumors or larger. The incidence of occult micrometastasis in Tl NO and T2NO tumors of the tongue is 30%, and many centers are now routinely using supraomohyoid neck dissection as a staging procedure in the NO neck for early lesions.7,8,9,‘0 It is my practice to consider supraomohyoid neck dissection for all T2 tumors of the tongue and floor of mouth with clinically negative necks. When these “early” tumors are over 4 mm thick, or have evidence of perineural spread, we consider supraomohyoid neck dissection to be the current standard of care.
References 1. Union Internationale Contre le Cancer: TNM Classification of Malignant Tumors (ed 4). Berlin, Germany, Springer-Verlay, 1987
2. Kraus DH, Vastola P, Huvas A, et al: Surgical management of squamous cell carcinoma of the base of the tongue. Am .I Surg 166:384, 1993 3. Hong WK, Endicott J, Im LM, et al: Prevention of second primary tumors with isotretroin in squamous-cell carcinoma of the head and neck. N Engl J Med 323:795, 1990 4. Evans SJW, Langdon JD, Rapidis AD et al: Prognostic significance of STNMP and velocity of tumor growth in oral cancer. Cancer 491773, 1982 5. Spiro RM, Huvos AG, Wong JY, et al: Predictive value of tumor thickness in squamous carcinoma confined to the tongue and floor of mouth. Am J Surg 152:345, 1986 6. Mohit-Tabatabai MA, Sobel MJ, Rush BF, et al: Relation of thickness of floor of mouth Stage I and II cancers to regional metastasis. Am J Surg 1.52:351, 1986 7. Byers RM: Modified neck dissection: A study of 967 cases from 1970 to 1980. Am J Surg 150:414, 1985 8. Spiro JD, Spiro RH, Shah JP, et al: Critical assessmentof supraomohyoid neck dissection. Am J Surg 156:286, 1988 9. Byers RM, Wolf PF, Ballantyne AJ: Rationale for elective modified neck dissection. Head Neck 10:160, 1988 10. Kowalski LP, Magnia J, W&man G, et al: Supra-omohyoid neck dissection in the treatment of head and neck tumors. Arch-Otolayngoyol Head and Neck Surg 119:958, 1993
955
ORD
J Oral Maxillofac 54:9%x, 1996
Surg
Discussion Primary
Oral Squamous Cell Carcinoma: A Review of 92 Cases
R.A. Ord, ivfD, DOS, FRCS University of Maryland Cancer Center,
Baltimore,
Maryland
The authors’ definition of oral cancer as a malignant disease affecting the “oral and oropharyngeal mucosa and the tongue” is not the universally accepted definition.’ Oropharyngeal cancers (ie, lesions of the anterior pillar, tonsil, soft palate, and base of tongue) appear to have a different biological behavior than oral cancers and are generally more radiation sensitive. The authors also exclude lip cancer, which is usually defined as an oral cavity cancer.’ The data from this series reflect similar findings of other authors regarding the epidemiology of oral cancer, except for the predominance of early cancers (stage I and II) in which 73% were documented. It is tempting to conclude that referrals to an oral and maxillofacial surgery unit would come primarily from dentists who are more expert at oral examination and detecting early disease. However, in my personal 5-year series of 159 patients with oral epidermoid carcinoma treated at the Oral and Maxillofacial Surgery Unit at the University of Maryland only 48% were stage I or II, despite a virtually 100% dental referral pattern. The authors’ improved survival rate is obviously related to the high percentage of early disease and the fact that only 7 (8%) of the patients had histologically proven nodal disease. Although it is true that the survival rate for oral cancer has changed little in the last 30 years, there has been a considerable change in the way these patients die. I disagree with the authors’ emphasis on locoregional disease to the exclusion of distant metastases and second primary cancers in the upper aerodigestive tract. Their contention that 80% of patient’s dying of oral cancer have locoregional disease is supported by a reference from 1960, and much has changed in the last 36 years. Indeed many recent papers have reported an 80% local and regional control.’ Although local recurrence and control in the neck continue to be a significant problem for stage III and IV patients, an increasing number of these patients succumb to distant rnetastases or second primary cancers. The authors’ short follow-up of 2-year survival is the reason that these problems did not become more evident in their series. The vast majority of local recurrences occur within 3 years of surgery (most in the first year, less in the second year, and the remainder in the third year) and, therefore, a 2-year survival follow-up will identify most persistent or locally recurrent disease. However, it is generally accepted that there is a 6% per year risk of developing a second primary cancer in the upper aerodigestive tract. This risk remains constant per year and does not lessen with time. Therefore, the longer the patient survives the initial primary, the greater the cumulative risk of a second cancer. As the majority of stage III and IV patients tend to die within
the first 3 years, and this risk is greatest for those patient’s with stage I and II disease who were “cured.” This explains the current interest in chemoprevention with retinoids3 Although the authors unsurprisingly show decreasing survival rates with increasing TNM stage, they were unable to show the importance of histological grading. Other authorities have shown the increased ability of the TNM system to stage tumors more accurately when histological grade (P) and site (S) are incorporated, (STNMP classification).4 More recently, head and neck surgeons have focused on tumor thickness as a prognostic indicator.5,6 This appears to be extremely valuable in predicting risk for nodal metastasis, and any further review by the authors of their oral cancer patients would be enhanced by including details of this variable. Lastly, only 28 of the reported patients (30%) underwent neck dissection, although 60 (62%), had T2 primary tumors or larger. The incidence of occult micrometastasis in Tl NO and T2NO tumors of the tongue is 30%, and many centers are now routinely using supraomohyoid neck dissection as a staging procedure in the NO neck for early lesions.7,8,9,‘0 It is my practice to consider supraomohyoid neck dissection for all T2 tumors of the tongue and floor of mouth with clinically negative necks. When these “early” tumors are over 4 mm thick, or have evidence of perineural spread, we consider supraomohyoid neck dissection to be the current standard of care.
References 1. Union Internationale Contre le Cancer: TNM Classification of Malignant Tumors (ed 4). Berlin, Germany, Springer-Verlay, 1987
2. Kraus DH, Vastola P, Huvas A, et al: Surgical management of squamous cell carcinoma of the base of the tongue. Am .I Surg 166:384, 1993 3. Hong WK, Endicott J, Im LM, et al: Prevention of second primary tumors with isotretroin in squamous-cell carcinoma of the head and neck. N Engl J Med 323:795, 1990 4. Evans SJW, Langdon JD, Rapidis AD et al: Prognostic significance of STNMP and velocity of tumor growth in oral cancer. Cancer 491773, 1982 5. Spiro RM, Huvos AG, Wong JY, et al: Predictive value of tumor thickness in squamous carcinoma confined to the tongue and floor of mouth. Am J Surg 152:345, 1986 6. Mohit-Tabatabai MA, Sobel MJ, Rush BF, et al: Relation of thickness of floor of mouth Stage I and II cancers to regional metastasis. Am J Surg 1.52:351, 1986 7. Byers RM: Modified neck dissection: A study of 967 cases from 1970 to 1980. Am J Surg 150:414, 1985 8. Spiro JD, Spiro RH, Shah JP, et al: Critical assessmentof supraomohyoid neck dissection. Am J Surg 156:286, 1988 9. Byers RM, Wolf PF, Ballantyne AJ: Rationale for elective modified neck dissection. Head Neck 10:160, 1988 10. Kowalski LP, Magnia J, W&man G, et al: Supra-omohyoid neck dissection in the treatment of head and neck tumors. Arch-Otolayngoyol Head and Neck Surg 119:958, 1993