Delays in Cancer Treatment Associated with Increased Mortality Rates

Research published in The BMJ found that even a 4-week delay of cancer treatment was associated with increased mortality rates across surgical, systemic treatment, and radiotherapy indications for 7 types of cancers.

Delays to cancer treatments is a problem in health systems around the globe, and the impact these delays have on mortality rates can now be quantified for prioritization and modeling, according to the researchers.

“A 4-week delay in treatment is associated with an increase in mortality across all common forms of cancer treatment, with longer delays being increasingly detrimental,” wrote the researchers. “In light of these results, policies focused on minimizing system level delays in cancer treatment initiation could improve population level survival outcomes.”

The data found that the association between treatment delays and mortality was statistically significant (P < 0.05) for 13 of 17 indications. Specifically, surgery findings saw a mortality risk of 1.06-1.08 (colectomy, 1.06; 95% CI, 1.01-1.12; breast surgery, 1.08; 95% CI, 1.03-1.13) for each 4-week delay.

More, with regard to radiotherapy, estimates were for radical radiotherapy for head and neck cancer (HR, 1.09; 95% CI, 1.05-1.14), adjuvant radiotherapy after breast conserving surgery (HR, 0.98; 95% CI, 0.88-1.09), and cervix cancer adjuvant radiotherapy (HR, 1.23; 95% CI, 1.00-1.50). There were no high validity data found for 5 of the radiotherapy indications or for cervical cancer surgery, and the estimates for systemic treatments varied among indications (HR range, 1.01-1.28).

The systematic review and meta-analysis included 34 studies for 17 indications with a population of over 1.2 million patients.

“The prevailing paradigm has been around access to new treatments to improve outcomes, but from a system level, gains in survival might be achieved by prioritizing efforts to minimize the time from cancer diagnosis to initiation of treatment from weeks to days,” wrote the researchers. “We acknowledge that treatment delays are multifactorial in cause and that patients should not start treatment before they are medically fit to do so, and have had completed all appropriate evaluations, however these data strongly support efforts to minimize system level delays.”

The study’s main strength is that the approach utilized help provide strong evidence of the association of treatment delay and mortality compared to if the researchers used randomized trials, which are not appropriate or feasible for this research.

The main limitation of this study is the “risk of residual confounding,” according to the researchers. They explain that patients with long treatment delays are more likely to see inferior results for comorbidity, treatment morbidity, or performance status. More, the data only applies to the cancer types analyzed and cannot be applied to other cancer specific treatment indications or subgroups.

Moving forward, the researchers suggest that implementing policies aimed to minimize system level delays for cancer treatments could improve the survival outcomes at the population level.

“The main purpose of this discussion is to highlight the need to minimize system level delays,” wrote the researchers. “We strongly emphasize that patients should not start surgery, systemic treatment, or radiotherapy until they are medically fit to do so, and have completed appropriate investigations.”

Reference:

Hanna TP, King WD, Thibodeau S, et al. Mortality due to cancer treatment delay: systematic review and meta-analysis. The BMJ. doi: https://doi.org/10.1136/bmj.m4087.