Stein-type shrinkage estimators in gamma regression model with application to prostate cancer data.

Gamma regression is applied in several areas such as life testing, forecasting cancer incidences, genomics, rainfall prediction, experimental designs, and quality control. Gamma regression models allow for a monotone and no constant hazard in survival models. Owing to the broad applicability of gamma regression, we propose some novel and improved methods to estimate the coefficients of gamma regression model. We combine the unrestricted maximum likelihood (ML) estimators and the estimators that are restricted by linear hypothesis, and we present Stein-type shrinkage estimators (SEs). We then develop an asymptotic theory for SEs and obtain their asymptotic quadratic risks. In addition, we conduct Monte Carlo simulations to study the performance of the estimators in terms of their simulated relative efficiencies. It is evident from our studies that the proposed SEs outperform the usual ML estimators. Furthermore, some tabular and graphical representations are given as proofs of our assertions. This study is finally ended by appraising the performance of our estimators for a real prostate cancer data.

Primary pelvic hydatid cyst in a postmenopausal female: a surgical challenge.

Primary pelvic hydatid cysts are a rare entity and are often overlooked as a differential diagnosis of a pelvic-space-occupying lesion particularly in non-endemic regions. Unpreparedness and a hasty decision on the surgical approach may end in life-threatening complications and systemic dissemination of the disease. We report the case of a 55-year-old postmenopausal woman with a history of two previous unsuccessful surgeries to remove pelvic cystic lesions due to dense adhesions between the surrounding gut wall, bladder, and the cyst wall. Clinical and imaging findings failed to diagnose the nature of the cysts, and a laparotomy was contemplated. On the third surgical attempt, the clinical suspicion was considered and by meticulous dissection the cysts were removed thoroughly without undue complications. In the postoperative follow-up period there was no sign of disease recurrence or dissemination.

Primary pelvic hydatid cyst in a postmenopausal female: a surgical challenge

Primary pelvic hydatid cysts are a rare entity and are often overlooked as a differential diagnosis of a pelvic-space-occupying lesion particularly in non-endemic regions. Unpreparedness and a hasty decision on the surgical approach may end in life-threatening complications and systemic dissemination of the disease. We report the case of a 55-year-old postmenopausal woman with a history of two previous unsuccessful surgeries to remove pelvic cystic lesions due to dense adhesions between the surrounding gut wall, bladder, and the cyst wall. Clinical and imaging findings failed to diagnose the nature of the cysts, and a laparotomy was contemplated. On the third surgical attempt, the clinical suspicion was considered and by meticulous dissection the cysts were removed thoroughly without undue complications. In the postoperative follow-up period there was no sign of disease recurrence or dissemination.