publication date: Jun. 14, 2019

Clinical Roundup

Cancer survivors predicted to number over 22M by 2030

There were more than 16.9 million Americans with a history of cancer on Jan. 1, 2019. The number is projected to reach more than 22.1 million by 2030 based on the growth and aging of the population alone, according to estimates from Cancer Treatment and Survivorship Statistics, 2019.

The report is produced every three years by the American Cancer Society in collaboration with NCI to help the public health community better serve this growing population. It appears in CA: A Cancer Journal for Clinicians, with a companion consumer edition published as Cancer Treatment and Survivorship Facts & Figures.

The number of cancer survivors continues to increase in the U.S., even as incidence rates are stable in women and declining in men. This is due to a growing and aging population, as well as increases in cancer survival due to advances in treatment and early detection.

The report uses the term “cancer survivor” to describe a person who has a history of cancer, from the time of diagnosis through the remainder of their life. However, it is important to note many people with a history of cancer do not embrace this term.

The report estimates there are currently 8.1 million males and 8.8 million females in the U.S. with a history of cancer. About two out of three cancer survivors (68%) were diagnosed five or more years ago and nearly one in five (18%) was diagnosed 20 or more years ago. Nearly two-thirds (64%) are aged 65 years or older. In addition, the report estimates that in the U.S., there are 65,850 cancer survivors 14 years and under and 47,760 ages 15 to 19.

The authors’ estimate of the number of cancer survivors in 2030 (22.1 million) is based on population projections produced by the U.S. Census Bureau, using current incidence, mortality, and survival rates. Changes in cancer occurrence and survival, due to advances in treatment and early detection, could further impact cancer prevalence.

Many survivors cope with long-term physical effects of treatment as well as psychological and socioeconomic sequelae.

Challenges also remain for survivors and their caregivers with regard to navigating the health care system, including poor integration of survivorship care between oncology and primary care settings, as well as financial and other barriers to quality care, particularly among the medically underserved.

“People with a history of cancer have unique medical, psychosocial, and economic needs that require proactive assessment and management by health care providers,” said Robin Yabroff, senior scientific director of Health Services Research and co-author of the report. “Although there are growing numbers of tools that can assist patients, caregivers, and clinicians in navigating the various phases of cancer survivorship, further evidence-based resources are needed to optimize care.”

The report said identification of the best practices for delivering quality rehabilitation and posttreatment cancer care is needed and points to ongoing efforts by the American College of Surgeons, the Alliance for Quality Psychosocial Cancer Care, and the American Cancer Society.

 

Identifying colorectal cancer subtypes in patients could lead to improved treatment decisions

Researchers at the USC Norris Comprehensive Cancer Center found identifying a metastatic colorectal cancer patient’s Consensus Molecular Subtype could help oncologists determine the most effective course of treatment. CMS also had prognostic value, meaning each subgroup was indicative of a patient’s overall survival, regardless of therapy.

The results are from the multi-center phase III CALGB/SWOG 80405 trial and published in the Journal of Clinical Oncology.

CMS categorizes colorectal cancer into four distinct, biologically characterized subgroups based on how mutations in the tumor behave. The subgroups were created using data from several research teams around the world that had previously analyzed tumors of colorectal cancer patients who were treated with surgery and adjuvant chemotherapy.

Although CMS classification is not based on clinical outcomes, there seemed to be patterns in how different subtypes responded to treatment.

“We wanted to understand the importance of CMS for patients with metastatic disease who are treated with the two most important first-line therapies,” said Heinz-Josef Lenz, professor of medicine in the Division of Oncology at the Keck School of Medicine of USC and J. Terrence Lanni Chair in Gastrointestinal Cancer Research at USC Norris. Lenz was the lead author on the study. “We anticipated that CMS had prognostic value, but we were impressed at how strongly CMS was associated with outcomes.”

The study compared the efficacy of two different therapies (chemotherapy and cetuximab vs. bevacizumab) on 581 metastatic colorectal cancer patients categorized by CMS. The data showed a strong association between a patient’s CMS subtype and both overall survival and progression-free survival. For example, patients in CMS2 had a median overall survival of 40 months compared to 15 months for patients in CMS1.

CMS also was predictive of overall survival among patients on either treatment, with patients in certain subtypes faring better on one therapy over the other. Survival for CMS1 patients on bevacizumab was twice that of those on cetuximab, whereas survival for CMS2 patients on cetuximab was six months longer than for bevacizumab.

“This study establishes the clinical utility of CMS in treating colorectal cancer,” said Lenz in a statement. “It also provides the basis for more research to uncover additional clinically significant predictive signatures within these subtypes that might better personalize patient care.”

Currently, it is not possible to order patient subtyping, though multiple efforts are underway to develop an assay approved for clinical use. Lenz estimates this could happen in a matter of months.

Until then, Lenz and his colleagues continue to analyze data from more than 44,000 samples of blood, tissue, and plasma in one of the largest, most comprehensive research efforts to characterize DNA, RNA, and germline DNA in colon cancer.

“This is only one study of many more to come that will help us understand this disease at the molecular level so we can provide better care for patients,” Lenz said.

CALGB/SWOG 80405 is supported by a grant from NCI. Genentech also funded the study. Primary study contributors included teams led by Alan Venook from the University of California, San Francisco; Federico Innocenti from the University of North Carolina, Chapel Hill; Omar Kabbarah from Genentech; and Fang–Shu Ou from Alliance for Clinical Trials in Oncology at Mayo Clinic.

 

Study suggests higher triple-negative breast cancer incidence among black women is not generalizable

A new study found substantial variation in the prevalence of triple-negative breast cancer among black women with breast cancer by birthplace in the U.S.

The prevalence of triple-negative breast cancer was highest among U.S.-born and Western-African–born black women, followed by Caribbean-born, and Eastern-African-born black women.

The study is published in the journal Cancer and its findings suggests the typical notion of higher proportional burden of triple-negative breast cancer among black women is not generalizable to all women of African descent.

Triple-negative breast cancer is approximately twice as common, both in proportion of breast cancers and in incidence rates among black women than white women in the U.S., a factor that is often considered as one contributor to lower breast cancer survival among black patients.

Black populations in the U.S. are diverse, comprising people born in the U.S. as well as immigrants from various countries. Rapidly growing numbers of immigrants from different national and social backgrounds during the most recent three or four decades have reshaped the overall black population in the U.S.

In 2013, about 9% of the black population was documented as being born outside the U.S., with approximately one-half born in the Caribbean, 35% born in Sub-Saharan Africa, and 9% born in Central and South America.

It is also notable the highest levels of within-population genetic diversity have been reported among persons who self-identified as blacks than among those in other racial groups. Still, nativity and geographic origin among black women has seldom been examined, even as nativity-related differences may improve the understanding of the etiologic heterogeneity of breast cancer.

Investigators, led by Hyuna Sung of the American Cancer Society, examined the prevalence of triple-negative and hormone receptor-negative breast cancer among black women in the National Program of Cancer Registries and U.S. Cancer Statistics.

The authors identified 65,211 non-Hispanic black women who were diagnosed with invasive breast cancer from 2010 through 2015 and who were recorded as being born in the U.S., East Africa, West Africa, or the Caribbean.

They found compared with U.S.-born black women, the prevalence rate ratio of triple-negative breast cancer was 13% lower among Caribbean-born women, and 46% lower 0.54 among Eastern-African–born black women.

“It is not clear what risk factors are associated with subtype prevalence by birthplace,” said Sung. “However, the similarity in breast cancer subtype prevalence between U.S.-born and Western-African–born blacks, contrasted against the differences with Eastern-African–born blacks, may in part reflect shared ancestry-related risk factors.”

The authors conclude “presenting breast tumor subtype in black women as a single category is not reflective of the diverse black populations in the nation. Their study “calls for a concerted effort for more complete collection of birthplace information in cancer registries.”

Copyright (c) 2019 The Cancer Letter Inc.