Lung Cancer Survival Worse Among Canadian Inuit in Quebec

Residents of an Inuit territory in Canada have worse survival following a diagnosis of lung cancer than similar patients living in Montreal, according to a new study.

The investigators conducted a retrospective matched cohort study comparing lung cancer survival for two populations treated at the McGill University Health Center: Residents of Montreal and of Nunavik, the Inuit homeland in Quebec where about a quarter of Canada’s Inuit population lives. The study found a significant difference, with Nunavik residents at a roughly 70% higher risk for death following a lung cancer diagnosis.

“If we can reduce the proportion of lung cancers that are diagnosed at inoperable later stages by detecting lung cancer earlier, that could potentially rapidly start reducing the disparity that we see,” study author Faiz Ahmad Khan, MD, MPH, a pulmonologist and associate professor of medicine at McGill University in Montreal, Quebec, Canada, told Medscape Medical News.

The study was published on February 20 in the Canadian Medical Association Journal.

Rates of Survival

Canadian Inuit are reported to have the highest incidence of lung cancer in the world, according to the authors. “Despite it having been known for many years that Canadian Inuit experience high rates of lung cancer, there was no information on whether Canadian health services were achieving the same outcomes among Inuit as we do among non-Inuit Canadian populations,” said Khan. “It’s a really important lack of evidence.”

The investigators compared 95 residents of Nunavik and 185 residents of Montreal, whom they separated into subgroups for non–small cell lung cancer and small cell lung cancer diagnoses. All patients were treated at the McGill University Health Center between 2005 and 2017. Median survival times among patients with non–small cell lung cancer were 321 days for Nunavik residents and 720 days for Montreal residents. Similarly, among patients with small cell lung cancer, median survival times were 190 days for Nunavik residents and 270 days for Montreal residents.

Small cell lung cancer and squamous cell carcinoma were more prevalent among Nunavik residents. These more aggressive forms were strongly associated with smoking tobacco, which was more common among Nunavik residents. However, the disparity in survival persisted when adjusting for factors including age, sex, cancer stage, and comorbidity. With these adjustments, Nunavik residents had a higher hazard of death (hazard ratio, 1.68).

Healthcare Structures

It’s important to focus on healthcare services and structures, rather than perpetuating an image of poor health, according to Khan, who also treats patients in Nunavik. “Inuit in Canada are a remarkably resilient population.”

When considering the study results, “a question all Canadians should ask is whether the healthcare services that are provided to Inuit are equitable and adequate for their specific context,” said Khan.

As part of the study’s analysis, the investigators worked with a Nunavik lung health research steering committee to interpret the findings — an important part of the study, Khan said. Because of small sample sizes, they were not able to identify treatment-related reasons for the shorter survival from the data. The authors noted, however, that fewer Nunavik residents received aggressive treatment. They suggested this may be due to a lack of prevention and detection resources in Nunavik, the burden of time away from community during chemotherapy treatment, and a lack of support for shared decision-making.

The authors recommended strengthening smoking cessation services and increasing access to screening, while being sure to approach patients in a culturally sensitive manner (eg, by involving Inuit cancer navigators to facilitate conversations).

Improving Outcomes

Commenting on the study for Medscape Medical News, Stephen Lam, MD, a professor of medicine at the University of British Columbia in Vancouver, British Columbia, Canada, said that several factors may account for shorter survival among Nunavik residents. These factors could include higher rates of small cell lung cancer and less aggressive treatment for both early and advanced-stage lung cancer, as outlined in the study.

Lam, who was not involved in the research, also noted that screening may fail to detect squamous cell carcinoma, which is difficult to detect until later stages, and small cell lung cancer, which can emerge rapidly. “A Nunavik Inuit–specific lung cancer plan that includes funding and resources for…diagnostic workup, treatment, and supportive care is a great idea to improve outcomes,” he added.

Overall, the study “outlines the lack of sufficient healthcare resources in Nunavik, such as a stable workforce and more hospitals, which makes prevention or detection that much harder,” said Natasha MacDonald, PhD, an assistant professor of education at McGill University who was not involved in the study. “Inuit are not sicker or weaker or ‘less than’ other human beings.”

MacDonald, who is from Nunavik, added that the study took a culturally responsible approach by consulting with Inuit involved in healthcare in Nunavik, which she says should be standard practice. In the future, disparities may be improved by reducing structural barriers to care and redesigning screening programs to meet Inuit needs, she added.

The study was funded by Rossy Cancer Network. Khan, Lam, and MacDonald reported no relevant financial relationships.

Gwendolyn Rak is a health reporter for Medscape Medical News based in Brooklyn, New York.