Pelvic irradiation does not increase the risk of hip replacement in patients with gynecological cancer

Figures & data

Table 1. Patient numbers and numbers of total hip replacements (THRs) by year of therapy

	1997–1998	1999–2000	2001–2002	2003–2004	2005–2006	Total
Breast cancer
Total number of patients	1,087	1,292	1,760	2,080	1,326	7,545
Number of THRs	35	65	65	58	30	253
Gynecological cancer
Total number of patients	81	229	236	254	162	962
Number of THRs	1	6	7	12	0	26

Figure 1. Dose distribution from radiotherapy of a cervical cancer patient. The yellow, light blue, and purple lines represent the 50-Gy, 45-Gy, and 25-Gy isodoses, repectively. The 4 radiation fields applied in patients with cervical cancer encompass the whole pelvis, the distal border of the fields being 0–10 mm below the obturator foramen. Depending on the radiotherapy technique used, the acetabula receive 30–50 Gy while the lateral parts of the hip are irradiated with 10–30 Gy.

Table 2. Numbers of cancer patients and of cancer patients who received a total hip replacement (THR), and risk estimates from a Cox model and a Fine and Gray model

					Cox			Fine and Gray
	n	THR	FU ^a	Age mean (SD)	HRR (95% CI)	p-value	subHRR (95% CI)	p-value	5-year CIF ^b (95% CI)	8-year CIF ^b (95% CI)
Gynecological cancer	962	26	7.0	58 (14)	0.79 (0.53–1.20)	0.3	0.80 (0.53–1.22)	0.3	1.35 (1.28–1.43)	2.72 (2.61–2.82)
Breast cancer	7,542	253	8.1	56 (11)	1 (ref)	–	1 (ref)	–	1.77 (1.74–1.80)	2.99 (2.95–3.03)

^a FU: follow-up, median years.

^b CIF: cumulative incidence function.

Figure 2. Risk of receiving a total hip replacement, calculated based on cumulative incidence function from the Fine and Gray competing-risk model (with death as the competing risk).