Cancer and the 10-Year Incidence of Chronic Low Back Pain in 407,314 Adults Followed in General Practices in Germany.

Objective: There is a scarcity of data on the long-term relationship between cancer and chronic low back pain (CLBP). Therefore, this retrospective cohort study investigated the association between cancer and the 10-year incidence of CLBP in Germany. Methods: Data collected in 1293 German general practices between 2005 and 2022 were used for the study. Patients diagnosed with cancer were matched to those without cancer (1:1) using a propensity score based on age, sex, the mean number of consultations per year during the follow-up, index year, and several chronic conditions. The index date was the consultation corresponding to cancer diagnosis in the cancer group and a random visit date in the noncancer group. The analyses included Kaplan-Meier curves with the log-rank test and Cox regression models adjusted for other frequent conditions. Results: There were 203,657 adults in the cancer group and 203,657 adults in the noncancer group. The mean (SD) age was 66.2 (14.6) and 66.0 (13.8) years in patients with and without cancer, respectively, with a proportion of women of 51.3-51.8%. Within 10 years of the index date, 16.1% of people with cancer and 18.8% of those without cancer were diagnosed with CLBP (p-value < 0.001). The Cox regression analysis corroborated this finding, as there was a negative and significant association between cancer and CLBP (HR = 0.87, 95% CI = 0.86-0.89). Conclusions: Cancer was not associated with increased odds of CLBP in the decade following its diagnosis in Germany. Due to limitations inherent to the data, caution should be taken when interpreting the study results.