Lack of primary care increases early breast cancer death risk

People who are marginalized or lack access to a primary care provider are at greater risk of early death from newly diagnosed (de novo) metastatic breast cancer, according to research in CMAJ (Canadian Medical Association Journal) https://www.cmaj.ca/lookup/doi/10.1503/cmaj.260156. The Ontario study examined people with de novo metastatic breast cancer, meaning their cancer had already spread to other parts of the body when it was first diagnosed. Researchers found that 23% died within 6 months of diagnosis.

"Data are lacking on early death from breast cancer and its association with sociodemographic factors in Canada," write Dr. Priya Thomas, plastic surgery resident, Western University, and Dr. Phillip Blanchette, ICES scientist and medical oncologist at London Health Sciences Centre (LHSC) and associate professor, Schulich School of Medicine & Dentistry, Western University, London, Ontario, with coauthors. "We conducted this study because patients diagnosed with de novo metastatic breast cancer are often vulnerable to disparities in health equity and access to care, and most previous studies investigating these issues have been conducted in the US."

One in 8 females will receive a diagnosis of breast cancer within their lifetime, and 3000 patients are diagnosed annually in Ontario. De novo metastatic breast cancer (stage IV) makes up 3% to 6% of all breast cancer diagnoses. While advances in treatment have improved survival for many people with metastatic breast cancer, disparities in access to care remain. The research team examined whether these disparities may help explain why some patients die shortly after diagnosis.

The research analyzed data from ICES on 4004 patients with de novo metastatic breast cancer who were treated in Ontario between 2010 and 2019. Using the Ontario Marginalization Index tool, the researchers examined how factors influence mortality, including measures of housing stability, income, age, and employment status.

In the 23% of people who died within 6 months, researchers found that older age, chronic illness, and higher levels of housing and income marginalization were associated with early death.

People linked to a family physician had 26% lower odds of early death, and they were also more likely to have received a mammogram within 2 years of diagnosis.

"Access to a primary care provider is a growing challenge in Canada, with 1 in 4 Canadians lacking regular access to primary care," write the authors. "Lack of access to primary care may negatively affect the timeliness of diagnosis and also lead to delays in starting important anticancer therapies."

The authors say the findings highlight the important role primary care plays in cancer prevention, diagnosis, and ongoing care.

"Primary care is pivotal in cancer prevention, screening, diagnosis, treatment support and adverse-effect management, symptom control, and psychosocial and palliative care. The demand for cancer care is rising exponentially, and specialist oncologists are unlikely to be able to meet these care needs alone."

The team also found an association between rural residence and early death. The researchers suggest this may reflect challenges associated with travelling for treatment, which is often coordinated through larger urban cancer centers.

"Optimizing cancer prevention and mammography screening in marginalized communities may reduce the likelihood of presenting with metastatic disease," the authors conclude. "Our findings highlight the need for better primary care access. Future studies to determine effective ways of optimizing rural delivery of cancer care and integration of virtual care are needed."

This research was supported in part by donor funding through London Health Sciences Foundation.