Is Chemotherapy a Good Choice for Neuroendocrine Tumors?

How effective is chemotherapy in treating neuroendocrine tumors (NETs)? Unfortunately, there is a lack of strong evidence from randomized trials, according to researchers from Gosford Hospital, University of Sydney; Royal North Shore Hospital, Northern Cancer Institute, and Macquarie University Hospitals, all in Australia; and Memorial Sloan Kettering Cancer Center in New York.

Related: Complex Malignancies: A Diagnostic and Therapeutic Trilemma

Few systematic reviews about chemotherapy for patients with NET have been published, and no meta-analyses have been done, the researchers say. They decided to rectify that deficiency and winnowed several hundred “potentially relevant” studies to 8 after examination.

Six studies compared one chemotherapy regimen against another (usually the standard streptozotocin [STZ] plus 5-fluorouracil [5FU]). Two studies compared chemotherapy with interferon (IFN). The researchers found no studies comparing chemotherapy with targeted therapy or somatostatin analogues and none comparing chemotherapy with best-supportive care.

Related: Harnessing Vaccines to Treat Cancers

Their analysis revealed no difference between STZ/5FU and other chemotherapies in response rate, progression-free survival (PFS), 1-year overall survival (OS), and OS. Response rates seemed to be higher for IFN, but no PFS or OS were demonstrated.

Any recommendations for chemotherapy as an option are “largely based on weak evidence,” the researchers charge. The problem, they say, is that the overall quality of the studies was poor. Only one met all features of a randomized trial with low risk of biases. The researchers cite inadequate randomization, lack of blinding, missing data, and selective reporting, among other flaws. In spite of the drawbacks of the studies they examined, their review remains the largest and most comprehensive review and appraisal of the existing evidence of chemotherapy in NET, the researchers say.

Related: Finding Synchronous Cancers

The past few years have seen the “evolution of an impressive array of systemic options,” they conclude, and “it remains to be seen whether chemotherapy shows enough efficacy compared to these options to warrant its side effect profile.” They point out that their review highlights not only the paucity of strong evidence, but also an urgent need of good randomized data—especially on the new, promising chemotherapeutic agents.

Source:

Wong MH, Chan DL, Lee A, et al. PLoS One. 2016;11(6):e0158140.
doi: 10.1371/journal.pone.0158140