Chemotherapy of metastatic Merkel cell carcinoma: case report and review of the literature

The natural history and management of Merkel cell carcinoma of the skin: a review of 22 patients treated at the Royal Marsden Hospital

Merkel cell carcinoma is a rare skin malignancy, which primarily affects the elderly. Currently, there is only limited data on the natural history of this condition and no consensus on its optimum management. We have reviewed the natural history and management of 22 patients with Merkel cell carcinoma, who were treated at the Royal Marsden Hospital between 1985 and 1994. The median age at diagnosis was 75 years (range 55-96), with the head and neck region being the most common site of disease (nine patients: 41%). Seventeen patients (77%) presented with skin disease, three (14%) with regional lymphadenopathy and two (9%) with metastatic disease. Of the Stage I patients, 41% developed local recurrence postoperatively at a median time to relapse of 12 months. Those with head and neck disease had the highest risk of local recurrence, which occurred in 62.5% of this group. Stage I patients also had a high risk of disease progression, with 53% developing regional lymphadenopathy or visceral metastases. The median survival for all disease stages was 47 months. The treatment of unresectable primary or recurrent disease with radiotherapy led to valuable long term control in four of nine patients treated. Six courses of chemotherapy were administered; one brief complete response was observed, occurring in a patient treated with cyclophosphamide, vincristine and doxorubicin. The data in this study confirms the predilection for the elderly and the aggressive nature of Merkel cell carcinoma, with only four of 17 Stage I patients remaining disease free. To clarify the role of adjuvant postoperative radiotherapy and to establish the appropriate use of chemotherapy in metastatic spread of this rare malignancy will require further studies with multicentre cooperation.

Merkel cell carcinoma of the skin

Primary neuroendocrine carcinoma of the skin or Merkel cell carcinoma is an aggressive primary neoplasm. It is commonly seen in the elderly, on the head, neck and extremities, where it can mimic a benign or less malignant skin tumour. Pathological examination shows a generally dense growth of small dark cells, with immunohistochemical evidence of neuroendocrine differentiation. The microscopic appearance is very similar to metastatic oat cell carcinoma from the lung and this must be excluded by clinical means and appropriate imaging studies. In this study we present 13 new cases of Merkel cell carcinoma (the largest published series in the UK) and summarize 214 cases from the literature in which the survival data are given. In our series, 5 of 13 patients died from spread of the Merkel cell carcinoma. From this and other studies, it appears that early diagnosis and wide local excision may be the only way to prolong survival. No other adjuvant therapy has proved effective.

Clinical efficacy of octreotide in the treatment of metastatic neuroendocrine tumors. A study by the Italian Trials in Medical Oncology Group

BACKGROUND

The unsatisfactory control of neuroendocrine tumor growth with chemotherapy and/or interferon (IFN-2a) stimulated us to investigate the role of the somatostatin analogue octreotide (SMS 201.995), which is reported to be highly effective in controlling carcinoid syndrome symptoms. Octreotide has been used in a wide range of doses, and it was postulated that higher doses might lead to an objective response.

METHODS

The aim of the present multicenter Phase II study was to determine the safety and efficacy of SMS 201.995 in controlling carcinoids and other neuroendocrine tumors. Fifty-eight patients were treated subcutaneously with 2 sequential doses of the drug (Sandostatina, Sandoz, Inc., S.b.A. Pharmaceuticals, Basel, Switzerland). The first 23 patients received 500 micrograms 3 times a day and the remaining 35 patients received 1000 micrograms 3 times a day. The treatment was continued until the tumor progressed.

RESULTS

All of the patients were adequately treated and evaluated. The predominant histotype was carcinoid, although there were instances of medullary thyroid carcinoma, pancreatic islet cell tumors, and Merkel cell carcinoma. Carcinoid syndrome was documented in 16 patients and abnormal urinary 5-hydroxyindoloacetic acid excretion in 15. The median treatment duration was 5 months (range, 2-31 months). The responses were evaluated in three categories: tumor regression for tumor growth control, symptom response, and biochemical response. There was an effect on tumor growth in two patients with carcinoids. Symptomatic control was achieved in 73% of patients and a biochemical response in 77% of patients. In twenty-seven patients, the disease stabilized for at least 6 months (range, 6-32+). The median survival time for all patients was 22 months (range, 1-32+).

CONCLUSIONS

In terms of tumor regression, octreotide is disappointing (partial response: 3%); symptomatic response and biochemical control are satisfactory. These data confirm that somatostatin analogues are comparable to interferons in the treatment of carcinoid syndrome, although other efforts are necessary to control tumor regression.

Merkel cell carcinoma. Diagnosis and treatment

BACKGROUND

Merkel cell carcinoma is an uncommon malignancy of the skin that often portends a poor prognosis. Since its first description by Toker in 1972, a plethora of case reports and articles regarding the etiopathogenesis and treatment have been published spanning multiple medical and surgical disciplines. Much confusion still exists regarding the diagnosis and treatment of this ominous tumor.

OBJECT

Through extensive review of the medical, surgical, and pathological literature, to collate the observations of multiple investigators and summarize these findings.

METHODS

Articles from journals of multiple subspecialties were carefully reviewed with particular emphasis placed on epidemiology, prognosis, histology, immunohistochemistry, electron microscopy, tumor origin, treatment, and work-up of Merkel cell carcinoma.

RESULTS

Merkel cell carcinoma is an aggressive malignant neoplasm. Local recurrence develops in 26-44% of patients despite therapy. Up to three-fourths of patients eventually develop regional nodal metastases with distant metastases occurring in one-third of all patients. Reported overall 5-year survival rates range from 30% to 64%.

CONCLUSION

Treatment recommendations unfortunately are based more on anecdotal than scientific data because of the rarity of the tumor and its recognized high risk. Most authors recommend wide local excision of the primary lesion and regional lymph node resection if lymph nodes are palpable followed by x-irradiation of both the postsurgical bed and lymph node basin. The role of elective lymph node resection in the absence of clinically positive nodes remains controversial.

Penile Merkel cell carcinoma

Merkel cell carcinoma of the genitalia is very rare and to date has been found only in vulvar mucosa. We describe an aggressive Merkel cell tumor in the frenulum of the penis with lymph node metastases, local recurrence, and eventually widespread dissemination. The primary tumor was associated with discontiguous squamous cell carcinoma in situ. This is the first report of Merkel cell (neuroendocrine) carcinoma in this anatomic site.

The importance of postoperative radiation therapy in the treatment of Merkel cell carcinoma

PURPOSE

To determine the role of postoperative radiation therapy in the treatment of Merkel cell carcinoma (MCC).

METHODS AND MATERIALS

Eighty patients with MCC of the skin were treated with curative intent at the Queensland Radium Institute between 1981 and 1991. Fifty-one patients (63.7%) were referred after initial biopsy for further treatment and 29 patients (36.3%) were referred with locally recurrent disease following primary surgery elsewhere. Thirteen patients (16.3%) presented with nodal disease without a clinically definable primary skin lesion.

RESULTS

Of the 80 patients, 38 had undergone surgery (S) alone, 34 surgery plus radiotherapy (S + RT), 7 RT after incomplete S, and 1 patient had chemotherapy (CT) plus RT. Overall survival at 36 months for all patients was 68%. All of the 38 patients treated with S alone relapsed. The median time to recurrence was 5.5 months. Ten of the 34 patients treated with S + RT relapsed. The median time to recurrence was 16.5 months. Of the 80 patients, 55 have relapsed after primary treatment, 25 have developed systemic metastases, and 26 patients have died as a direct result of MCC.

CONCLUSION

Our large series confirms earlier reports from this Institute and highlights the importance of S + RT over S alone in preventing local recurrence of this highly malignant skin cancer.

A phase II trial of dacarbazine, fluorouracil and epirubicin in patients with neuroendocrine tumours. A study by the Italian Trials in Medical Oncology (I.T.M.O.) Group

BACKGROUND

Previous experiences in the treatment of neuroendocrine tumours have demonstrated some activity of single agents such as adriamycin, fluorouracil (FU), streptozotocin and dacarbazine (DTIC). Opinions concerning the usefulness of polychemotherapy in carcinoid tumours are discordant, whereas better results have been achieved in other endocrine pancreatic neoplasms. Based on this background, we used multidrug chemotherapy with DTIC, FU and epirubicin in the treatment of different neuroendocrine tumours.

METHODS

The study involved 38 pts with progressive and measurable disease. The treatment schedule was FU 250 mg/m2 i.v., epirubicin 25 mg/m2 i.v., and DTIC 200 mg/m2 i.v. on days 1, 2 and 3 every 3 weeks.

RESULTS

The responses achieved by histologic types were carcinoids 2/20, medullary thyroid carcinoma 1/7, neuroendocrine tumours 1/6; and Merkel cell carcinoma 3/5. The median duration of response was 5 months (range 2-11). Stable disease was observed in 13 cases (34%). Out of the 18 cases in progression, 17 had not responded to previous medical treatment. No symptom control was observed in 4 pts with carcinoid syndrome. Treatment toxicity was moderate and included nausea and vomiting, alopecia, leukopenia and mucositis.

CONCLUSIONS

Our results document the moderate efficacy of the regimen in all of the histologic types. The major difference in comparison with previous studies was the lower response rate observed in patients with neuroendocrine tumours.

Merkel cell carcinoma: an aggressive skin neoplasm

Merkel cell carcinoma (MCC) is an aggressive skin neoplasm of neuroendocrine origin. To clarify those factors important in improving survival, we retrospectively reviewed the charts of all patients with Merkel cell carcinoma treated at two tertiary referral centers. Eighty percent of the patients with stage I disease were initially treated with local therapy alone, while all of the patients with stage II disease were treated with local and regional therapy. The overall survival rate for all patients was 64%. Regardless of stage, patients treated with local excision alone had a 52% 5-year survival rate, while patients treated with local excision and lymph node dissection had an 87% survival rate. We conclude that the aggressive nature of this tumor warrants radical therapy.

Neurologic complications of Merkel cell carcinoma

We describe a 61-year-old man with a multiple neurologic complication of Merkel cell carcinoma, a rare skin cancer. An enhancing brain mass, and cytologically proven leptomeningeal disease produced a succession of symptoms including seizures, bilateral radiculopathies, myoclonus, a cauda equina syndrome and altered mental status. Aggressive treatment prolonged his survival marginally.

Merkel cell carcinoma

Merkel cell carcinoma is a malignant neuroendocrine tumor with features of epithelial differentiation. Biologically aggressive, it may be difficult to diagnose and, particularly in its late stages, even more difficult to treat effectively. This article addresses what is known and what is still controversial about the histogenesis, diagnosis, and management of Merkel cell carcinoma and the structure and function of the Merkel cell from which it is believed to be derived. The incidence, clinical presentation and diagnosis, ultrastructure, immunocytochemistry, treatment, and prognosis of this tumor will be discussed.