Weekly carboplatin reduces toxicity during synchronous chemoradiotherapy for Merkel cell carcinoma of skin.
OBJECTIVE
The toxicity of radiotherapy (RT) combined with weekly carboplatin and adjuvant carboplatin and etoposide was prospectively assessed in a group of patients with high-risk Stage I and II Merkel cell carcinoma of the skin. This regimen was compared with the Trans-Tasman Radiation Oncology Group 96:07 study, which used identical eligibility criteria but carboplatin and etoposide every 3 weeks during RT.


METHODS
Patients were eligible if they had disease localized to the primary site and lymph nodes, with high-risk features. RT was delivered to the primary site and lymph nodes to a dose of 50 Gy and weekly carboplatin (area under the curve of 2) was given during RT. This was followed by three cycles of carboplatin and etoposide. A total of 18 patients were entered into the study, and their data were compared with the data from 53 patients entered into the Trans-Tasman Radiation Oncology Group 96:07 study.


RESULTS
Involved lymph nodes (Stage II) were present in 14 patients (77%). Treatment was completed as planned in 16 patients. The weekly carboplatin dose was delivered in 17 patients, and 15 were able to complete all three cycles of adjuvant carboplatin and etoposide. Grade 3 and 4 neutrophil toxicity occurred in 7 patients, but no cases of febrile neutropenia developed. Compared with the Trans-Tasman Radiation Oncology Group 96:07 protocol (19 of 53 cases of febrile neutropenia), the reduction in the febrile neutropenia rate (p = 0.003) and decrease in Grade 3 skin toxicity (p = 0.006) were highly statistically significant.


CONCLUSIONS
The results of our study have shown that weekly carboplatin at this dosage is a safe way to deliver synchronous chemotherapy during RT for MCC and results in a marked reduction of febrile neutropenia and Grade 3 skin toxicity compared with the three weekly regimen.
Poulsen
Michael
M
Division of Cancer Services, Princess Alexandra Hospital, University of Queensland, Brisbane, QLD, Australia. michael_poulsen@health.qld.gov.au
Walpole
Euan
E
Harvey
Jennifer
J
Dickie
Graeme
G
O'Brien
Peter
P
Keller
Jacqui
J
Tripcony
Lee
L
Rischin
Danny
D
D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage; D016190:Carboplatin / Q000008:administration & dosage*; D015266:Carcinoma, Merkel Cell / Q000188:drug therapy* / Q000532:radiotherapy*; D002868:Chromosomal Proteins, Non-Histone; D003131:Combined Modality Therapy; D029721:Drosophila Proteins; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008875:Middle Aged; D010865:Pilot Projects; D011836:Radiation Tolerance / Q000187:drug effects*; D011855:Radiodermatitis / Q000209:etiology / Q000517:prevention & control*; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; C527369:aust protein, Drosophila; D016190:Carboplatin