Sunday InBriefs: Highlights from ASCO18

Sunday InBriefs: Highlights from ASCO18

Systemic Therapy Costs and Use in Patients With mCC

Abstract LBA3579

Use and cost of systemic therapy for metastatic colorectal cancer is significantly higher for patients in western Washington state in the United States compared to those in British Columbia, Canada, with no significant differences in overall survival.

Researchers analyzed data from 1,622 patients in British Columbia and 575 in Washington. Patients in British Columbia were more likely to be older (median age, 60 vs. 66) and male (57% vs. 48%, p £ 0.01) than those in Washington. The most common first-line regimen in British Columbia was FOLFIRI plus bevacizumab (32%), whereas FOLFOX was the most common first-line regimen in Washington (39%).

The mean monthly cost of first-line therapy per patient was $12,345 in the United States vs. $6,195 in Canada (p £ 0.01) for all regimens assessed. Mean lifetime monthly costs were also significantly higher in Washington ($7,883 vs. $4,830, p £ 0.01). Overall median survival of patients receiving therapy was similar (21.4 months in Washington vs. 22.1 months in British Columbia), with similar overall median survival among those who did not receive therapy (5.4 months in Washington vs. 6.3 months in British Columbia).

Sex May Affect Toxicity of Adjuvant Chemotherapy in Patients With Colorectal Cancer

Abstract 3603

Researchers compared major adverse events (nausea, vomiting, stomatitis, diarrhea, leucopenia, neutropenia, anemia, thrombocytopenia, and neuropathy) among 28,636 patients (54% men) in the ACCENT database treated with adjuvant chemotherapy after curative resection of colorectal cancer. Their results show that women had a significantly higher risk of several grade 3/4 toxicities in three of the chemotherapy regimens evaluated: single-agent fluoropyrimidine (5-fluorouracil [5-FU]), FOLFIRI, and FOLFOX.

The greatest differences between the sexes were seen in those treated with 5-FU, in which nearly twice as many women as men experienced nausea/vomiting (8.1% vs. 4.3%). A greater percentage of women also experienced stomatitis (7.2% vs. 4.4%); diarrhea (20.0% vs. 16.0%); leucopenia (5.6% vs. 3.1%); and neutropenia (16.0% vs. 11.0%). Under the FOLFOX regimen, women were nearly twice as likely to experience nausea and vomiting (13.0% vs. 6.8%), diarrhea (21.0% vs. 15.0%), and neutropenia (27.0% vs. 18.0%). Significant differences in the FOLFIRI regimen included nausea/vomiting (13.0% vs. 9.6%), diarrhea (21.0% vs. 16.0%), leucopenia (11.0% vs. 7.4%), and neutropenia (40.0% vs. 26.0%).

Although differences in perception could account for the differences in gastrointestinal effects, the researchers noted that they do not explain the significant differences in neutropenia. They recommended additional investigation and suggested that clinicians may need to consider sex-specific strategies for drug dosing and supportive care.  

–Debra Gordon