ASCO Highlights 2019

Mehmet Sitki Copur, MD

The 2019 American Society of Clinical Oncology (ASCO) Annual Meeting, which took place May 31–June 4 in Chicago, drew more than 32,000 oncology specialists from around the world. The theme of this year’s ASCO conference was Caring for Every Patient, Learning from Every Patient. Among the topics of interest covered were new approaches to surmount limited access to cancer care and the latest advances in targeted therapies for pancreatic, prostate, and pediatric cancers.

More than 2,400 abstracts were presented at the meeting. These are some notable examples[1]:

Breast cancer

Low-fat Dietary Pattern and Long-Term Breast Cancer Incidence and Mortality: The Women’s Health Initiative Randomized Clinical Trial

A low-fat diet is linked to lower rates of breast cancer, according to results from the Women’s Health Initiative Dietary Modification trial (Abstract 520), a randomized, controlled clinical trial performed at 40 US centers.[2] In total, 48,835 postmenopausal women aged 50 to 79 years were randomized to either a usual diet comparison group (60%) or a dietary intervention group (40%). The intervention group set goals to decrease fat intake to 20% of total energy and boost consumption of vegetables, fruits, and grains.

After 8.5 years of dietary intervention, breast cancer incidents and breast cancer deaths in the intervention vs control group were lower, but not significantly so. Deaths after breast cancer from any cause, however, significantly decreased in the intervention group during the intervention (hazard ratio [HR], 0.65; 95% CI, 0.45–0.95), as well as on total follow-up of 16.1 years. Moreover, the decrease continued at 19.6 years of follow-up, along with a significant drop in deaths from breast cancer (HR, 0.79; 95% CI, 0.64–0.97).

“Adoption of a low-fat dietary pattern associated with increased vegetable, fruit, and grain intake demonstrably achievable by many significantly reduced the risk of death from breast cancer in postmenopausal women,” wrote authors led by Rowan Chlebowski, MD, PhD, of the Los Angeles BioMedical Research Institute at Harbor-UCLA Medical Center. “These findings provide the first randomized clinical trial evidence that a dietary change can reduce a postmenopausal woman’s risk of dying from breast cancer.”[2]

Bladder cancer

EV-201: Results of Enfortumab Vedotin Monotherapy for Locally Advanced or Metastatic Urothelial Cancer Previously Treated with Platinum and Immune Checkpoint Inhibitors

Following treatment failures with platinum-based and/or immunotherapy with checkpoint inhibitors, there are no effective treatment options for locally advanced or metastatic urothelial cancer. Treatment with enfortumab vedotin (EV) yielded responses-no growth or tumor shrinkage-in 44% of patients with locally advanced or metastatic types of urothelial cancer, according to the results of an open-label phase II study.[3,4] Furthermore, 12% of patients experienced a complete response with no detectable cancer signs. (Abstract LBA4505). The median overall survival time in this study of 125 patients was 11.7 months. In total, 41% of patients with cancer who did not respond to a checkpoint inhibitor responded to EV, and 38% of those with liver metastases responded. EV was well tolerated, with fatigue being the most common adverse effect (50%).[3]

“These phase II results replicate the phase I results very closely, which is not often the case in clinical trials,” said lead author Daniel P. Petrylak, MD, a Professor of Medicine (Medical Oncology) and Urology at Yale Cancer Center, in an ASCO press release. “The fact that we have a therapy that can help people who don’t benefit from checkpoint inhibitors is very gratifying.”[4]

Multiple myeloma

E3A06: Randomized Phase III trial of Lenalidomide vs Observation Alone in Patients with Asymptomatic High-Risk Smoldering Multiple Myeloma

Treatment with single-agent lenalidomide vs observation resulted in a 72% reduction in progression-free survival (PFS) at 3 years in patients with intermediate- to high-risk smoldering multiple myeloma, according to the results of a phase III trial.[5,6]

The overall response rate in the phase II study was 47.7%. In the phase III study, it was 48.9% for the lenalidomide group only. In phase II, the median follow was 71 months, and in phase III, it was 28 months. No differences in quality of life were observed.[5,6]

“There’s no question that patients with multiple myeloma need immediate treatment to reverse evidence of organ damage, but a challenge we’ve struggled with is trying to identify patients without organ damage who are at highest risk of disease progression, and trying to intervene,” lead author Sagar Lonial, MD, of Winship Cancer Institute of Emory University, said in an interview with ASCO.[6]

“We showed, in the largest randomized study to date in smoldering myeloma, that we can prevent the development of symptomatic myeloma in a significant fraction of patients,” he commented.[6]

Colorectal cancer

Long-Term Survival After Laparoscopic vs Open Resection for Colorectal Liver Metastases

Laparoscopic vs open surgery did not change survival rates in patients with colorectal cancer who were having liver metastases removed, according to results of the phase III OSLO-COMET trial (Abstract LBA3516). Of note, no difference between groups was observed with respect to extent of complete tumor removal or amount of tissue resected past the observable tumor.[7]

“After many years of improvements in laparoscopic surgery, we now have results showing that survival is as good with this procedure as with open surgery, and morbidity is lower, so we expect that this will cause a shift to even more operations on the liver being done laparoscopically,” stated team leader Bjørn Edwin, MD, PhD, from the Intervention Centre and the Department of HPB Surgery at Oslo University Hospital, Norway, in an ASCO press release.[8]

Medicaid Expansion Impact on Racial Disparities in Cancer Care

Finally, in news that was encouraging to all in attendance, researchers showed that implementation of Affordable Care Act (ACA) Medicaid expansions led to more timely cancer treatment in African Americans, thus reducing racial disparities with respect to access to care(Abstract LBA1).[9]

In the study, which included 34,067 patients (median age, 57 years; 12% African American), racial disparities were noted pre-expansion. Specifically, African Americans were 4.9 percentage points (%pt) less likely to be administered timely treatment. The Medicaid expansion trended toward a rise in timely treatment for all patients (P = .05). This expansion, however, was correlated with a higher benefit for African American patients (6.9 %pt) vs Caucasian patients (1.8 %pt).

Patients selected had advanced or metastatic cancer (non–small-cell lung, breast, urothelial, gastric, colorectal, renal cell, prostate, and melanoma) and were diagnosed between January 1, 2011, and December 31, 2018, using the nationwide Flatiron Health electronic health record-derived database. “Timely treatment” was defined as first-line treatment started within 30 days of advanced or metastatic diagnosis. Covariates controlled for included race, age, sex, practice type, cancer type, stage, and unemployment rate.[9]

“Implementation of Medicaid expansions as part of the ACA differentially improved African American cancer patients’ receipt of timely treatment, reducing racial disparities in access to care,” concluded the authors, led by Blythe J. S. Adamson, PhD, MPH, a Senior Quantitative Scientist at Flatiron Health in New York.

References:

1. American Society of Clinical Oncology. ASCO announces top studies to be presented at 2019 annual meeting. Available at: https://www.asco.org/about-asco/press-center/news-releases/asco-announces-top-studies-be-presented-2019-annual-meeting. Accessed June 30, 2019.

2. Chlebowski RT, Aragaki AK, Anderson GL, et al. Low-fat dietary pattern and long-term breast cancer incidence and mortality: The Women’s Health Initiative randomized clinical trial. J Clin Oncol. 2019;37(suppl):abstr 520. Available at: https://abstracts.asco.org/239/AbstView_239_253759.html. Accessed June 30, 2019.

3. Petrylak DP, Balar AV, O’Donnell PH, et al. EV-201: results of enfortumab vedotin monotherapy for locally advanced or metastatic urothelial cancer previously treated with platinum and immune checkpoint inhibitors. J Clin Oncol. 2019;37(suppl):abstr LBA4505. Available at: http://abstracts.asco.org/239/AbstView_239_265881.html. Accessed June 30, 2019.

4. American Society of Clinical Oncology. Novel targeted-antibody treatment produced responses in nearly half of patients with advanced urothelial cancer. Available at: https://www.asco.org/about-asco/press-center/news-releases/novel-targeted-antibody-treatment-produced-responses-nearly. Accessed June 30, 2019.

5. Lonial S, Jacobus SJ, Weiss M, et al. E3A06: Randomized phase III trial of lenalidomide versus observation alone in patients with asymptomatic high-risk smoldering multiple myeloma. J Clin Oncol. 2019;37(suppl):abstr 8001. Available at: https://abstracts.asco.org/239/AbstView_239_258227.html. Accessed June 30, 2019.

6. American Society of Clinical Oncology. Evidence builds for treating smoldering myeloma. Available at: https://www.ascopost.com/issues/may-25-2019/evidence-builds-for-treating-smoldering-myeloma/. Accessed June 30, 2019.

7. Fretland AA, Aghayan D, Edwin B; OSLO COMET Trial Group. Long-term survival after laparoscopic versus open resection for colorectal liver metastases. J Clin Oncol. 2019;37(suppl):abstr LBA3516. Available at: http://abstracts.asco.org/239/AbstView_239_265401.html. Accessed June 30, 2019.

8. American Society of Clinical Oncology. Colorectal cancer patients with liver metastases live just as long after laparoscopic surgery as open surgery. Available at: https://www.asco.org/about-asco/press-center/news-releases/colorectal-cancer-patients-liver-metastases-live-just-long. Accessed June 30, 2019.

9. Adamson BJS, Cohen AB, Estevez M, et al. Affordable Care Act (ACA) Medicaid expansion impact on racial disparities in time to cancer treatment. J Clin Oncol. 2019;37(suppl):abstr LBA1. Available at: https://abstracts.asco.org/239/AbstView_239_257961.html. Accessed June 30, 2019.