Faculty Bibliography

The prognostic relevance of the extent of nodal metastases, lesion thickness, level of invasion, site of lesion, satellitosis, age, sex, and year of diagnosis and treatment were assessed in 213 consecutive patients with pathologic Stage II malignant melanoma (157 with clinical Stage I disease and 56 with clinical Stage II disease). Of these factors, only three were significant: 1) clinical status of the lymph nodes (p less than 0.0001); 2) thickness of the primary lesion in the ranges of less than 2.0 mm, 2.0 to 4.9 mm, and 5.0 mm or greater (p = 0.002); and 3) level of invasion (p = 0.0002). The extent of nodal metastases in those patients with clinical Stage I disease was not significant. The difference in survival between patients with clinically negative/histologically positive nodes (clinical Stage I) and clinically positive/histologically positive nodes (clinical Stage II) was apparent throughout the follow-up period. The 5- and 10-year survival rates for the clinical Stage I patients were 44% and 28%, respectively, and for the clinical Stage II patients 21% and 12%, respectively (p less than 0.0001). A 5-year cumulative survival rate of 65% was achieved for clinical Stage I patients having primary lesions of less than 2.0 mm in thickness, while it was 19% for patients having primary lesions of 5.0 mm or more in thickness. For pathologic Stage II malignant melanoma patients, prognosis is most dependent on the clinical status of the lymph nodes, not on the number of lymph nodes with micrometastases

In summary, we believe that in the following situations elective regional lymph node dissection should not usually be performed: Patients whose primary malignant melanomas are in situ or have a maximal thickness of less than 1.0 mm. The incidence of regional node metastases in the latter group is so low that regional lymph node dissection is not justified. Patients whose primary malignant melanomas are in the midline of the head and neck or the trunk. Bilateral nodal dissections in these two regions of the body in the absence of a clearly demonstrable therapeutic advantage are not justified. Whether radioisotopic localizing studies will add greater definition to this group remains to be seen. Elderly patients or those with serious intercurrent disease. They should not undergo elective nodal dissection unless the primary malignant melanoma is very thick and lies directly over its nodal group. Patients with systemic metastases. For all remaining patients, the therapeutic or at very least prognostic advantages of elective regional lymph node dissections have been outlined. Conversely, an adverse effect on the course of the disease has never been demonstrated. We adhere to a policy that includes these procedures as primary therapy, provided they are performed with minimal morbidity. Should a surgeon elect not to perform such a procedure in the absence of clinically suspicious lymphadenopathy, careful clinical evaluation at 2-month intervals for the first 2 to 3 years following primary excision, with more prolonged intervals thereafter, would appear prudent. Until such time as effective means of eradicating systemic metastatic malignant melanoma exist, surgery remains the treatment of choice for this potentially fatal neoplasm. Efforts to develop effective adjuvant treatment based on the precise means of delineating prognosis that have thus far been developed has eluded investigators. A reasoned surgical approach is still required in our judgment until the identification and treatment of premalignant precursor lesions are universal or effective systemic therapy is available

Ionizing radiation as used for therapy for cancer is probably weakly carcinogenic at worst. The probability that cancers will be induced at a distance from the treatment volume is so small that it can only be inferred from experiences with large populations exposed to much higher radiation doses. The risk of cancer in and adjacent to the treatment volume also appears to be small, especially in adults. Intensive radiotherapy or radiotherapy of children 20 to 30 years ago appears to have induced secondary cancers in about 3 to 4 per cent of those treated, but modern practice has every expectation of reducing this incidence. No precise risk factor can be offered, but it seems likely that less than 3 to 4 per cent is a reasonable projection. The reason for the low carcinogenicity in the treatment volume probably lies in the fact that the irradiation dose is high and many cells are killed rather than transformed. The frequency of the induction of radiogenic cancer adjacent to or near the treatment volume is expected to vary according to the tissue exposed. It is not estimated to exceed a few per cent in the worst instances (for example, breast and thyroid gland) and is much less than 1 per cent in most tissues

Elective regional lymph-node dissection was performed on 98 patients with clinical Stage I cutaneous malignant melanoma and 26 of them were found to have microscopic evidence of metastases. The histology of the primary lesions was reviewed in order to find possible prognostic parameters that would allow prediction of nodal involvement. There was an increased risk of occult lymph node metastases with increasing thickness of the primary lesions. While this trend was not found to be statistically significant, no occult lymph node metastases were found for lesions less than 1.0 mm in thickness. Significant features included mitotic figures, 'prognostic index,' and plasma cells within the infiltrate. A multiple logistic regression analysis identified three groups of patients with low, medium, and high risk of occult metastases, based on thickness, location, and plasma cells. The correlation between plasma cells and the incidence of metastases in lymph nodes might represent an immunologic phenomenon