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PURPOSE Hematologic toxic effects of peptide receptor radionuclide therapy (PRRT) can be permanent. Patients with underlying clonal hematopoiesis (CH) may be more inclined to develop hematologic toxicity after PRRT. However, this association remains understudied. MATERIALS AND METHODS We evaluated pre- and post-PRRT blood samples of patients with neuroendocrine tumors. After initial screening, 13 cases of interest were selected. Serial blood samples were obtained on 4 of 13 patients. Genomic DNA was analyzed using a 100-gene panel. A variant allele frequency cutoff of 1% was used to call CH. RESULT Sixty-two percent of patients had CH at baseline. Persistent cytopenias were noted in 64% (7 of 11) of the patients. Serial sample analysis demonstrated that PRRT exposure resulted in clonal expansion of mutant DNA damage response genes ( TP53, CHEK2, and PPM1D) and accompanying cytopenias in 75% (3 of 4) of the patients. One patient who had a normal baseline hemogram and developed persistent cytopenias after PRRT exposure showed expansion of mutant PPM1D (variant allele frequency increased to 20% after exposure from < 1% at baseline). In the other two patients, expansion of mutant TP53, CHEK2, and PPM1D clones was also noted along with cytopenia development. CONCLUSION The shifts in hematopoietic clonal dynamics in our study were accompanied by emergence and persistence of cytopenias. These cytopenias likely represent premalignant state, as PPM1D-, CHEK2-, and TP53-mutant clones by themselves carry a high risk for transformation to therapy-related myeloid neoplasms. Future studies should consider CH screening and longitudinal monitoring as a key risk mitigation strategy for patients with neuroendocrine tumors receiving PRRT.

The combination of cisplatin, 5-fluorouracil, and cetuximab is a standard treatment for patients with recurrent/metastatic head and neck cancer, with a high rate of toxicity. Identifying less toxic, equally effective regimens is imperative. Therefore, in the current study, the authors investigated first-line treatment with an all-oral regimen of capecitabine and lapatinib.Patients were required to have incurable head and neck cancer of any primary site other than the nasopharynx, an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 to 2, and no prior exposure to capecitabine or lapatinib. Subjects were treated with capecitabine at a dose of 1000 mg/m(2) twice daily and lapatinib at a dose of 1250 mg daily. Capecitabine was administered for 14 days of each 21-day cycle for 4 cycles. Lapatinib was administered daily until disease progression. The primary outcome was overall survival.A total of 44 subjects were accrued between November 13, 2009 and April 29, 2014. Approximately 38.6% of the sample had an ECOG PS of 0, 52.3% had an ECOG PS of 1, and 9.1% had an ECOG PS of 2. Approximately 81.8% were male and the median age of the patients was 62 years. Prior attempts at curative treatment with chemotherapy had been used in 68.2% of patients (platinum was used in 55.8%). There was no grade 5 toxicity noted (toxicity was graded according to National Cancer Institute Common Terminology Criteria for Adverse Events [version 3.0]). The most common adverse events were diarrhea (18.2% of patients with grade 3) and rash (13.6% of patients with grade 3). The primary objective was met; the median overall survival was 10.7 months (90% confidence interval [90% CI], 8.7-12.9 months). The overall response rate was 25% (90% CI, 15%-38%). The median progression-free survival was 4.2 months (90% CI, 3.6-5.1 months). The results were not substantially different when subdivided by p16 status. Only 2 patients were positive for human epidermal growth factor receptor 2 by immunohistochemistry.The current study met its primary objective of survival comparable to the combination of cisplatin, 5-FU and cetuximab regimen, and the toxicity of this all-oral regimen was tolerable. Cancer 2016;122:2350-2355. © 2016 American Cancer Society.