Parity and Time Interval Since Childbirth Influence Survival in Endometrial Cancer Patients

Abstract

Parity and time interval since last birth have been found to be associated with the risk of endometrial cancer, but few previous studies have examined whether these reproductive factors have prognostic impact. We examined this issue among 740 nulliparous and 3355 parous endometrial cancer patients diagnosed in Norway during the period 1961-1999. The mean age at diagnosis was 55.7 years (range, 25-74 years). Hazard ratios (HRs) with 95% confidence intervals were calculated in Cox proportional regression models. Parous women had significantly (P < 0.001) better prognosis than nulliparous women. In analyses adjusted for age at diagnosis, clinical stage, and histological type, the HR for parous versus nulliparous women was 0.68 (95% confidence interval, 0.57-0.82). The prognostic impact of parity was restricted to patients with endometrioid tumors (P = 0.014, test for interaction) and appeared to be most pronounced in women without metastases (P = 0.14, test for interaction). Moreover, the improved prognosis was strongest for women with the shortest time interval since last childbirth. The HRs (nulliparous women as reference) were 0.51, 0.60, and 0.80 for women less than 15, 15 to 24, and 25 years or more since birth (P < 0.001). The observed beneficial effect of pregnancies may be related to a strong exposure to progesterone during pregnancy. However, it is possible that tumors developing in nulliparous and parous women have different biological features. Further knowledge on this issue may provide valuable information that can be used for individualized treatment.

Long-term survival of endometrioid endometrial cancer patients

“…Age at diagnosis, age at menarche, parity, menopausal age, menstrual status, hormonal contraception, and hormone replacement therapy are well known risk factors for developing the cancer [2, 3, 11, 13, 17, 18], but as in our study, their role as prognostic factors predicting survival remains controversial. Only higher number of pregnancies was correlated with better DFS, and our results match well with those of Alkbretsen et al [19] reporting the relationship between obstetric history and prognosis in endometrioid endometrial cancer patients. They found better survival in parous than nulliparous women, and in the study the improved effect was strongest for women with the shortest time interval since the last childbirth.…”

Hospital-based Study of Endometrial Cancer Survival in Mumbai, India

“…In analyses adjusted for age at diagnosis, clinical stage, and histological type, the HR for parous versus nulliparous women was 0.68 (95% confidence interval, 0.57-0.82) (Albrektsen, et al, 2009) and also reports were similar in an earlier study (Bratos et al, 2002). Similar observations were found in the present study where nulliparous women had poor prognosis than parous women.…”

Prognostic Impact of Parity in 493 Uterine Sarcoma Patients

“…1 It has been noted that these tumors have clinical characteristics more similar to high-grade endometrial carcinomas, 1,2,4,5 but differences also exist. 6Y8 Similar to findings for patients with endometrial carcinoma, 9,10 nulliparity was found in 1 study to adversely affect prognosis in patients diagnosed with CS. 11 Two other studies, 12,13 however, could not confirm this finding.…”

“…1,11 In relation to our finding of a beneficial prognostic impact of parity in endometrial cancer patients, 10 we hypothesized that pregnancy progesterone may have had a favorable effect in the very early and undetected phase of disease. In view of their finding among CS patients, Marth et al 11 hypothesized that a pregnancy-induced alteration in protein content in uteri, or immunologic mechanisms, could lead to improved resistance to dissemination.…”