Treatment of metastatic malignant melanoma with dacarbazine plus tamoxifen

Estrogen and progesterone receptor analysis in pregnancy-associated melanoma: absence of immunohistochemically detectable hormone receptors

The role of estrogen in the initiation and progression of melanoma remains unclear. Some findings that suggest a hormonal role in melanoma initiation or progression include the following: (1) melanomas arising during pregnancy are thicker than those in nonpregnant women, (2) pregnant women with stage II (regional nodal metastases) melanoma have a worse prognosis than nonpregnant women of similar stage, and (3) melanoma is rare prior to puberty. Although biochemical assays have shown that estrogen-binding proteins are present in malignant melanoma, studies using a sensitive and more specific immunohistochemical technique have not found estrogen receptors (ERs) in melanoma. In our laboratory an immunohistochemical technique using monoclonal antibody H222 can detect ER in tumors with receptor levels lower than 9 fmol/mg protein and detects ER in a variety of tissues and species. In addition, monoclonal antibody KD68 is used to detect progesterone receptors immunohistochemically. We studied 14 cases of pregnancy-associated melanoma. None of our cases, ranging from melanoma in situ to metastatic melanoma, showed positive nuclear staining for ER, nor did any of these cases show positive immunohistochemical staining for progesterone receptor. Despite the wide tissue and species distribution of ER detected by the monoclonal antibody H222, this immunohistochemical technique does not appear to be useful in the study of possible hormonal effects on the progression of malignant melanoma. The estrogen-binding proteins in melanoma detected by biochemical techniques in previous studies probably are distinct from the well-defined human ER.

Regulation of insulin-like growth factors by antiestrogen

Insulin-like growth factors are potent mitogens for breast cancer cell proliferation. This effect is modulated by the circulatory and extracellular IGFBPs as well as by the affinity of ligand binding receptors on the target cells. Antiestrogens have been shown to reduce both circulatory and microenvironmental IGF levels and thus suppress the IGF-I-induced growth of both ER-positive and ER-negative breast cancer cells. However, the effects of antiestrogens in down regulation of type I IGF receptor and in altering the autophosphorylation tyrosine kinase activity of EGF receptors are mainly observed in ER-positive cells. Furthermore, alteration of IGFBP by antiestrogens such as a marked increase of IGFBP-I production have been shown to inhibit the proliferative effect of IGF-I on ER-positive, but stimulate this effect, on ER-negative cells. Such differential effects from IGF receptor and IGFBP may explain the clinical outcome that tumor regression from antiestrogens is mainly observed in ER-positive type. This assumption based on IGF regulation alone is certainly an oversimplistic view amid the complexity of autocrine, paracrine, and endocrine functions.

Phase II trial of procarbazine, vincristine and lomustine (POC) chemotherapy in metastatic cutaneous malignant melanoma

40 patients with symptomatic metastatic melanoma were treated with procarbazine, vincristine and lomustine (POC). 4 patients had received chemotherapy previously. Responses were seen in 8 patients (20%), 4 of whom had a complete remission. All responding patients had some tumour shrinkage after one cycle. The median duration of response was 27 weeks, with 2 patients remaining in complete remission at 6 and 6.5 years. The median survival for the whole group was 22 weeks, whilst that of the responding patients was 35 weeks. Using conventional anti-emetics, the principal toxicities were nausea and vomiting, severe in 15% of cycles. Other nonhaematological toxicity was uncommon. Neutropenia (WHO grade 3 or 4) occurred in 11% of cycles and thrombocytopenia in 8%. The response rate of metastatic melanoma to POC chemotherapy was similar to other cytotoxic regimens though toxicity, other than nausea and vomiting, was minimal. The rapid response allows patients with unresponsive disease to be identified early, avoiding continuing toxicity.

Malignant melanoma of the perineum

We conducted a retrospective review of the medical records of 18 patients diagnosed at the University of Colorado with perineal melanoma. Clinical characteristics including Clark's level, recurrence, and survival were studied. Ten patients (55.6%) had vulvar melanoma, 2 patients (11.1%) had vaginal disease, and the remaining 6 patients (33.3%) had primary rectal melanoma. All patients were treated surgically at the time of diagnosis. At a median follow-up of 32.7 months, 15 patients had evidence of recurrence. Nine of these patients are dead and six are alive with disease. The average time to recurrence was 14 months and the most common site was the regional lymph nodes in 10 of the 14 patients (71.4%). This study confirms the poor prognosis in perineal melanoma and the only effective treatment to date is early diagnosis and complete resection.

Tamoxifen modulation of cisplatin resistance in patients with metastatic melanoma. A biologically important observation

BACKGROUND

Treatment with the four-drug combination of dacarbazine (DTIC), carmustine (BCNU), cisplatin (DDP), and tamoxifen (TAM) has resulted in an overall response rate of more than 50% in patients with metastatic melanoma. Deletion of TAM from the regimen resulted in a decrease in the response rate to 10%, suggesting an important role for TAM. The authors have subsequently demonstrated that TAM is highly synergistic with DDP in a human melanoma cell line, T-289, which supports the clinical observation that TAM is important in this regimen. The authors conducted a clinical trial to determine whether the addition of TAM can overcome established DDP resistance in patients with malignant melanoma.

METHODS

Patients with metastatic melanoma were initially treated with DDP 100 mg/m2 alone until they demonstrated DDP resistance. On the next cycle of treatment, patients received TAM 40 mg by mouth four times a day on the day before DDP treatment followed by 20 mg by mouth daily for the rest of the 3-week cycle plus the same dose of DDP.

RESULTS

Among 24 patients treated with DDP alone there were one complete and two partial responses. Twenty patients, in whom single-agent DDP failed, were treated with the combination of TAM and DDP. Of these 20 patients, 19 were evaluable for response. Among these 19 patients, there were three partial responses (16%) and three mixed responses (16%), for an overall response rate of 32% (0% was expected) (P < 0.001). If the three mixed responses are eliminated, the statistical significance is of borderline significance (P = 0.058).

CONCLUSIONS

The addition of TAM to DDP can overcome established DDP resistance in a subset of patients with metastatic melanoma.

An evaluation of the influence of reproductive factors on the risk of metastases from uveal melanoma

BACKGROUND

There is a paucity of data concerning the possible role played by hormonal factors in the risk of metastases from intraocular melanomas.

METHODS

The authors studied the influence of post-diagnosis pregnancy and oral contraceptive use in a group of women of reproductive age (45 or younger) who were treated for uveal melanoma by proton beam irradiation. A baseline reproductive history had been collected before irradiation for all women, and interim reproductive data were collected by mailed questionnaire.

RESULTS

In this age group, the overall rate of metastasis among women was similar to that of men treated during the same interval (adjusted rate ratio: 1.28; 95% confidence interval: 0.62-2.67). A total of 24 full-term pregnancies were reported among the 139 women still menstruating at diagnosis. Twenty-three women reported regular oral contraceptive use. Metastases developed in 15 of the 139 women. Compared with other women in the series, rates of metastases were not higher among the women who reported pregnancies (P = 0.932) or oral contraceptive use (P = 0.424) after diagnosis.

CONCLUSION

Although based on limited numbers, results suggest that the hormonal environment has no appreciable influence on risk of metastases in younger women with uveal melanoma.

The impact of generalized malignant melanoma on quality of life evaluated by the EORTC questionnaire technique

Eighty-nine patients with generalized malignant melanoma, 63% men and median age 53 years, were included in a longitudinal quality of life (QOL) study before the start of chemotherapy. QOL was assessed by the EORTC core questionnaire technique (QLQ-C36), a study-specific melanoma (MM) module and the Hospital Anxiety and Depression (HAD) scale. The questionnaires displayed good psychometric qualities and were able to document the florid symptomatology of disseminated melanoma. They were well accepted by the patients. Before treatment the patients reported a relatively low symptom burden, good physical and social functioning, moderate psychological distress and a high overall QOL rating during the past week. Fatigue and pain were the most frequent symptoms reported. The QOL measurement differentiated between subgroups of patients differing in performance status and the tumour burden. We conclude that the EORTC questionnaire technique is feasible and clinically relevant in generalized malignant melanoma patients.

Advances in systemic treatment of malignant melanoma

This paper reviews recent developments in the systemic treatment of advanced malignant melanoma. In the introduction emphasis is given to prevention and early detection of this disease. Metastatic malignant melanoma patients have a median survival of less than 1 year in the most favourable situation. Adjuvant chemotherapeutic treatment after initial surgery has not had an impact on prognosis, while immunological manipulations with interferon alfa or other agents may prove beneficial after primary surgery. In advanced disease which cannot be palliated by surgery, many approaches are under investigation. Modulation of the patient's immune response can be achieved with vaccines, monoclonal antibodies, interleukin-2 and interferons, as single agents or in combination between themselves or with peripheral blood mononuclear cells or with tumour infiltrating lymphocytes or even with chemotherapy. Immunological approaches yield a 20-30% response rate, with some possibly long-term responses. Chemotherapeutic agents have a 10-30% response rate, which is usually of short duration. Combinations of chemotherapeutic agents can increase the response rate to 50%, but an impact on ultimate survival seems unlikely. Randomised studies have shown that modulation of chemotherapy with interferon or tamoxifen improves response rates. Clinicians should be encouraged to enter their patients with malignant melanoma in therapeutic trials.

Tamoxifen enhances the cytotoxic effects of the nitrosourea fotemustine. Results on human melanoma cell lines

Fotemustine (Fote) is a new amino acid-linked chloroethyl nitrosourea which has been shown to be useful in disseminated malignant melanoma. The aim of the present study was to analyse the cytotoxic effects resulting from the combination of anti-oestrogens and Fote on human melanoma cell lines. The anti-oestrogens tested were tamoxifen (TMX, 5 x 10(-7) mol/l and 5 x 10(-6) mol/l) and 4OH TMX (5 x 10(-8) mol/l and 5 x 10(-7) mol/l). As a preliminary step, a series of nine human melanoma cell lines was screened in order to identify and quantify the presence of oestradiol receptors (ER) in these cell lines. This led to the selection of an ER-positive (+) cell line. The drugs alone or in combination were then tested against CAL 1 ER (+) and CAL 7 ER (-) melanoma cell lines. Different sequences of drug combinations were tested using clinically compatible drug concentrations. For CAL 1 cells, there was a growth inhibitory effect induced by the anti-oestrogens given alone. Overall, the presence of the anti-oestrogens resulted in higher cytotoxic effects than when cells were exposed to Fote alone. The lowest IC50 Fote values as compared to Fote alone were generated by the sequences in which the anti-oestrogens were administered before Fote. Significantly, these associations with anti-oestrogens enabled the IC50 values of Fote to be reduced by up to 80%. Globally, TMX and 4OH TMX had similar synergistic effects. TMX and 4OH TMX had a modest influence on Fote cytotoxic effects against CAL 7 ER-negative cells. These data may be useful for optimal planning of future clinical trials for malignant melanoma using anti-oestrogens and nitrosoureas.

Topical toremifene: a new approach for cutaneous melanoma?

The distribution of topically applied toremifene (0.5-1 mg/day for 5 days) in the ultraviolet B (UVB)-induced Monodelphis domestica opossum melanoma model was examined. The mean concentration of toremifene measured in the skin was 1200 nmol/g, or > 500 times that detected in any other tissues (blood, brain, liver, testicles, heart, uterus, eyes). In plasma, toremifene could be detected in only one animal of six (0.04 nmol/ml). Intraperitoneal administration of 0.5 mg toremifene daily for 5 days in three female animals resulted in a mean uterus concentration of 22.9 nmol/g, or 400-fold that achieved by topical administration of 0.5 mg/day in three other female Monodelphis (0.05 nmol/g). The cytostatic effect of toremifene was studied in three human melanoma cell lines and three experimental cell lines derived from UVB-induced melanocytic nevi in M. domestica. Toremifene had a cytostatic effect on all cell lines (50% growth-inhibitory concentrations, 5.8-9.6 microM). Topical toremifene administration yields high local concentration with minimal systemic distribution. In addition, toremifene has a cytostatic effect at achievable concentrations in a variety of melanomatous cell lines.