ASCO Highlights: Sorafenib stalls disease progression in DTC; longer-term tamoxifen reduces breast cancer recurrence and death

On Sunday, ASCO released data from five pivotal studies on reducing cervical cancer deaths worldwide, first therapies for two rare cancers, and treatment advances for breast and brain cancers.


Effective, affordable cervical cancer screening strategy promises to save thousands of women’s lives in low-income countries

A large, randomized study conducted among 150,000 women in India over a period of 15 years reports that biennial visual inspection with acetic acid (VIA), or vinegar, delivered by primary health workers, reduced cervical cancer mortality by nearly one-third (31 percent). Cervical cancer is the leading cause of cancer death among women in many developing countries, where there is little or no access to Pap screening. The researchers estimate this strategy could prevent 22,000 cervical cancer deaths every year in India and close to 73,000 in resource-poor countries worldwide.

First effective biologic treatment for women with metastatic or relapsed cervical cancer

A randomized phase III study assessing two different chemotherapy regimens with or without bevacizumab (Avastin) finds that adding bevacizumab prolongs overall survival by an average of four months compared to chemotherapy alone. The study represents the first time a targeted drug has significantly prolonged overall survival for women with metastatic or relapsed cervical cancer. The study was performed by the Gynecologic Oncology Group.

Overall, the median survival for patients who received bevacizumab plus chemotherapy was 17.0 months vs. 13.3 months for those who received only chemotherapy. Tumor shrinkage rates were higher in patients who received the bevacizumab (48 percent vs. 36 percent) and responses lasted longer. Analysis of quality of life data will be reported at the ASCO Annual Meeting. Generally, the results indicate that survival benefit associated with bevacizumab did not come at the cost of diminished quality of life.

Adding bevacizumab to standard chemotherapy does not benefit patients with newly diagnosed glioblastoma

In this study, women aged 35-64 years with no prior history of cancer were randomly assigned to biennial screening with VIA (75,360 women) or no screening (76,178 women), which is the current standard of care in India given that the infrastructure does not allow for country-wide Pap screening. According to the authors, in accordance with international standards for clinical research — including cancer screening trials – interventions are tested against the local standard of care. The control group received one round of cancer education, at enrollment. Women in the control group were asked to report to the primary health workers any signs/symptoms of cervical cancer that they noticed on the basis of what they had learnt during the initial cancer education sessions. The health workers then directed them to the Tata Memorial Hospital (where they received diagnosis and treatment at no cost) or to other nearby facilities of their choice. The screening group received four rounds of VIA screening and cancer education at 24-month intervals between 1998 and 2010. All trial participants were offered free cervical cancer treatment, if diagnosed.A randomized phase III study finds no overall survival improvement from the addition of bevacizumab to standard first-line chemoradiation for glioblastoma. Patients who received bevacizumab also experienced more side effects compared to those treated with chemoradiation alone. The findings suggest that it should not be a part of first-line therapy for these patients with glioblastoma.

Sorafenib is first drug in three decades to be shown effective for certain aggressive thyroid cancers

A randomized phase III study, DECISION, finds that the targeted drug sorafenib (Nexavar) stalls disease progression by five months in patients with metastatic differentiated thyroid cancer that has progressed despite standard radioactive iodine (RAI) therapy. If approved by the FDA, sorafenib would become the first new active drug for this form of thyroid cancer in 40 years.

In this study, 417 patients with metastatic, RAI-resistant differentiated thyroid cancer were randomly assigned to receive sorafenib or placebo. Patients were allowed to cross over to the sorafenib arm upon disease progression. The median progression-free survival was 10.8 months in the sorafenib group vs. 5.8 months in the placebo arm. Tumor shrinkage of 30 percent or more was observed in12.2 percent and 0.5 percent of patients in the sorafenib and placebo arms, respectively. An additional 42 percent of patients in the sorafenib arm had stable disease for 6 months or longer for a disease control rate of 54 percent, compared with a disease control rate of 34 percent in the placebo arm. Overall survival data are not yet mature.

Longer tamoxifen therapy substantially reduces risk of breast cancer recurrence and death

The median overall survival was not statistically different between the two groups (16.1 months with placebo vs. 15.7 months with bevacizumab). The median progression-free survival was longer in the bevacizumab group relative to the placebo group (10.7 months vs. 7.3 months), but the difference did not reach the pre-set level of significance prescribed for this study. A subgroup analysis based on molecular markers (MGMT methylation status and a nine-gene expression signature) found no subgroup with improved survival using bevacizumab.Ten years of adjuvant treatment with tamoxifen provides women with estrogen-receptor-positive (ER+) breast cancer greater protection against late recurrence and death from breast cancer than does the current standard of only five years of tamoxifen, according to the British aTTom study. While side effects are also increased with longer tamoxifen use, the researchers conclude that the overall benefits greatly outweigh the risk of continuing therapy. The findings from aTTom, a Phase III randomized study, complement and confirm the results of the recently published international study, ATLAS.