A new study reported in the Journal of Clinical Oncology has shown that fewer than half of women with metastatic ovarian cancer are receiving an effective treatment that could improve ovarian cancer outcomes.

Since 2006, the National Cancer Institute (NCI) has recommended the use of intraperitoneal (IP) chemotherapy for the treatment of metastatic ovarian cancer, based on evidence that administering chemotherapy directly into the abdomen, along with the usual IV method, could add 16 months or more to women’s lives. The new study looked at the adoption rate of IP chemotherapy at six large U.S. hospitals that were all members of the National Comprehensive Cancer Network, an alliance of 26 large cancers centers that creates widely used practice guidelines for cancer treatment. The researchers found that at these centers, IP treatment is not used as much as experts thought it should be. 

According to the researchers, the use of IP chemotherapy increased after the NCI recommendation, but then it plateaued. The adoption of IP chemotherapy varied by institution from 4%–67%, with an average of 43% of eligible patients with metastatic ovarian cancer receiving modified IP regimens at treatment initiation, despite the fact that the treatment has been associated with improved overall survival. The low the adoption rate and the amount of variation among the medical centers were surprising. The researchers noted that at smaller, less prestigious hospitals, the adoption rates would be even lower. 

The researchers speculated that a variety of factors may be influencing the underuse of this treatment. IP chemotherapy is harder to administer than IV therapy, and some healthcare providers may still doubt its benefits. In addition, IP treatment is time consuming to administer and uses generic drugs, so it is not as profitable as other treatments. IP treatment requires the implantation of a port into the abdominal wall to infuse drugs directly into the abdomen and immerse any cancer cells left in chemotherapy. 

The new study also confirmed the findings of previous research that IP treatment helps women live longer. Among the 500 women who had IP treatment in the study, 81% were still alive three years later, compared with 71% of women who had only IV chemotherapy. 

The study also addressed the issue of the toxicity of IP treatment, finding that its side effects were less severe than IV treatment and the completion rates were similar: 89% of women who received IP treatment finished the planned course, compared with 91% who received IV treatment.