Treatment of advanced neuroendocrine tumours using combination chemotherapy with lomustine and 5-fluorouracil.

OBJECTIVE

Combination chemotherapy with the two agents streptozotocin (SZT), which is a nitrosurea, and 5-fluorouracil (5-FU), an alkylating agent, has a long-established role in the treatment of neuroendocrine tumours; however, it is often accompanied by considerable toxicity, and it has not been assessed in a comparative manner with other current chemotherapy regimens. In order to assess the therapeutic response and adverse effects using an alternative nitrosurea, lomustine (CCNU), which has a different side-effect profile, in combination with 5-FU, we have reviewed all patients with neuroendocrine tumours who received this form of treatment in our department.

DESIGN

Retrospective analysis of the case notes of patients with metastatic neuroendocrine tumours who received treatment with the combination of CCNU and 5-FU, and who were followed up according to a defined protocol in a given time frame.

PATIENTS

Thirty-one patients with metastatic neuroendocrine tumours (18 with carcinoid tumours, five islet-cell tumours, five chromaffin-cell tumours and three medullary carcinoma of the thyroid) treated with the combination of CCNU and 5-FU, and when necessary additional therapy, over a 22-year period, were included in this analysis.

MEASUREMENTS

The symptomatic, hormonal and tumoural responses before and after chemotherapy with the combination of CCNU and 5-FU over a median follow-up duration of 25 months (range 9-348 months) were recorded. Of the 31 patients (16 males; median age 52 years, range 20-86 years), eight (four males; median age 61 years, range 30-74 years) were treated with the combination of CCNU and 5-FU alone (Group 1), whereas the other 23 patients (12 males; median age 47 years, range 20-86 years) received additional therapy with other chemotherapeutic regimens, somatostatin analogues, alpha-interferon or radiolabelled meta-iodobenzylguanidine (131I-MIBG) therapy (Group 2).

RESULTS

A total of 121 therapeutic cycles was administered (mean 3.9, range 1-14 cycles). None of the patients obtained a complete tumour response. A partial tumour response (not a complete but a 50% or greater reduction of all measurable tumour) was seen in six out of the 29 patients (21%) (four out of eight in Group 1 and two out of 21 in Group 2, respectively). There was no tumour progression in eight out of the 29 patients (27.5%) (one out of eight in Group 1 and seven out of 21 in Group 2, respectively). The median survival over the period of the study was 48 months (95% confidence interval, CI, 22-74 months). The overall 5-year survival rate was 42% (95% CI, 17-67%) for all patients and 50% (95% CI, 18-83%) for the carcinoid group alone, according to Kaplan-Meier analysis. A complete or partial symptomatic response was obtained in 12 out of 27 (44%) patients who presented with symptoms (four out of eight in Group 1 and eight out 19 in Group 2, respectively) and a complete or partial hormonal response in eight out of 19 patients (42.1%) who presented with hormonally active disease (two out of four in Group 1 and six out of 15 in Group 2, respectively). Nine out of the 15 (60%) patients with carcinoid tumours who presented with symptoms obtained a symptomatic response, five out of 10 patients (50%) a hormonal response, and four out of 16 (25%) patients a partial tumoural response, respectively. The combination of CCNU and 5-FU was safe and well tolerated. Serious side-effects necessitating the termination of CCNU and 5-FU were seen only in two patients, and mainly consisted of reversible bone marrow suppression. No chemotherapy-related death was recorded.

CONCLUSIONS

Chemotherapy with CCNU and 5-FU, either alone or in combination with other therapeutic modalities, produces considerable symptomatic and hormonal improvement and moderate tumour regression/stabilization according to currently accepted WHO criteria, particularly in patients with metastatic gastroenteropancreatic neuroendocrine tumours with minimal adverse effects. However, long-term survival was still relatively poor. It may therefore be a valuable additional therapl was still relatively poor. It may therefore be a valuable additional therapeutic option, particularly for well-differentiated carcinoid and islet-cell tumours, but mainly reserved for when there is no response or progression of the disease after currently available first-line treatment with somatostatin analogues or radiopharmaceuticals.