Increased risk of pelvic fracture after radiotherapy in rectal cancer survivors: A propensity matched study

Abstract

To determine whether radiotherapy ( RT ) can increase pelvic fracture risk in rectal cancer survivors. Rectal cancer patients who underwent curative surgery between 1996 and 2011 in Taiwan were retrospectively studied using the National Health Insurance Research Database ( NHIRD ) of Taiwan. ICD ‐9 Codes 808, 805.4‐805.7, 806.4‐806.7, and 820 (including pelvic, sacrum, lumbar, and femoral neck fracture) were defined as pelvic fracture. Propensity scores for RT , age, and sex were used to perform one‐to‐one matches between the RT and non‐ RT group. Risks of pelvic and arm fractures were compared by multivariable Cox regression. Of the 32 689 patients, 7807 (23.9%) received RT , and 1616 suffered from a pelvic fracture (incidence rate: 1.17/100 person‐years). The median time to pelvic fracture was 2.47 years. After matching, 6952 patients each in the RT and non‐ RT groups were analyzed. RT was associated with an increased risk of pelvic fractures in the multivariable Cox model (hazard ratio ( HR ): 1.246, 95% confidence interval ( CI ): 1.037‐1.495, P = 0.019) but not with arm fractures ( HR : 1.013, 95% CI : 0.814‐1.259, P = 0.911). Subgroup analyses revealed that RT was associated with a higher pelvic fracture rate in women ( HR : 1.431, 95% CI : 1.117‐1.834) but not in men, and the interaction between sex and RT was significant ( P = 0.03). The HR of pelvic fracture increased 2‐4 years after RT ( HR : 1.707, 95% CI : 1.150‐2.534, P = 0.008). An increased risk of pelvic fracture is noted in rectal cancer survivors, especially women, who receive RT .

Sacral insufficiency fracture following rectal cancer treatment – case report

“…However, it can be misinterpreted as local recurrence. Improvement in radiotherapy technique reduces the risk of IF in rectal cancer survivors [6]. MRI scans are recommended to make accurate diagnosis of IF.…”

“…Pelvic insufficiency fracture is detected in 3.3-7.1% of cases after radiotherapy, and can be noted between 2 months to 8 years after treatment [4]. A study performed by Yu-Mei Kang et al [6], confirmed that pelvic fracture risk is higher after 2-4 years of follow-up after RT. On this case, it is advised that physicians pay more attention to pelvic fractures during the first four years of follow-up among rectal cancer patients who receive pelvic RT.…”

“…On this case, it is advised that physicians pay more attention to pelvic fractures during the first four years of follow-up among rectal cancer patients who receive pelvic RT. Pain is the most common symptom of post-RT pelvic fracture whilst around 20%-50% of people are asymptomatic [6].…”

Relations Between Bone Quantity, Microarchitecture, and Collagen Cross‐links on Mechanics Following In Vivo Irradiation in Mice

“…We found an association between cortical thinning and reduced fatigue life that was only significant within all the 12-week groups. It has been shown that the incidence of insufficiency fractures post-radiotherapy increases after 1 year (2) and that the median time to fracture after treatment is approximately 2.5 years (4) . Taken together, these findings would question the role of irradiation alone, and consider the role of irradiation plus time on insufficiency fractures (24)(25)(26)(27) such as those following radiation therapy, which have been reported to occur after repetitive loading at magnitudes well below the bone's strength (57,58) .…”

“…The effects of exposure to ionizing radiation on bone strength is of interest for numerous reasons, including oncologic radiotherapy and space exploration, among others. Following oncologic radiotherapy, fragility fractures in cancer survivors are a known complication (1)(2)(3)(4)(5)(6)(7)(8)(9)(10) . For example, the risk of hip insufficiency fracture in postmenopausal women treated for cervical, rectal, or anal cancer (9) or in men treated for prostate cancer (10) is increased at sites directly exposed to radiation (relative risk: 1.66, 1.65, 3.14, and 1.76, respectively).…”