Alterations in Hormone Levels After Adjuvant Chemoradiation in Male Rectal Cancer Patients

Effect of preoperative radiotherapy for rectal cancer on spermatogenesis

In this study, preoperative radiotherapy for rectal cancer was found to result in a dose-dependent impairment of spermatogenesis and Sertoli cell function, reflected both by decreased sperm count and characteristic changes in hormonal response, with signs of partial recovery between 12 and 24 months after surgery. Decreased semen volume was also observed, indicating ejaculatory tract dysfunction, that seemed to be longer-lasting and not related to testicular dose. This threatens fertility in men treated for rectal cancer, and suggests that pretreatment cryopreservation and anticonception after treatment should be discussed individually.

Serum testosterone changes in patients treated with radiation therapy alone for prostate cancer on NRG oncology RTOG 9408

Objectives

We reviewed testosterone changes for patients who were treated with radiation therapy (RT) alone on NRG oncology RTOG 9408.

Methods and materials

Patients (T1b-T2b, prostate-specific antigen <20 ng/mL) were randomized between RT alone and RT plus 4 months of androgen ablation. Serum testosterone (ST) levels were investigated at enrollment, RT completion, and the first follow-up 3 months after RT. The Wilcoxon signed rank test was used to compare pre- and post-treatment ST levels in patients who were randomized to the RT-alone arm.

Results

Of 2028 patients enrolled, 992 patients were randomized to receive RT alone and 917 (92.4%) had baseline ST values available and completed RT. Of these 917 patients, immediate and 3-month post-RT testosterone levels were available for 447 and 373 patients, respectively. Excluding 2 patients who received hormonal therapy off protocol after RT, 447 and 371 patients, respectively, were analyzed. For all patients, the median change in ST values at completion of RT and at 3-month follow-up were −30.0 ng/dL (p5-p95; −270.0 to 162.0; P < .001) and −34.0 ng/dL (p5-p95, −228.0 to 160.0; P < .01), respectively.

Conclusion

RT for prostate cancer was associated with a median 9.2% decline in ST at completion of RT and a median 9.3% decline 3 months after RT. These changes were statistically significant.

Assessment of testicular dose during preoperative radiotherapy for rectal cancer

BACKGROUND

Radiotherapy (RT) for rectal cancer can have adverse effects on testicular function resulting in azoospermia and low testosterone levels. Variability of testicular dose (TD) due to differences in position of testes has been assessed with scrotal dosimeters and resulted in substantial variability of delivered TD. The aim of this study was to estimate planned and delivered TD using a treatment planning system (TPS).

METHODS

In 101 men treated with RT for rectal cancer the cumulative mean TD (mTD) was calculated by TPS based on plan-computed tomography (CT) to evaluate the effect of different predictors on planned TD. The delivered TD was estimated by TPS based on repeated cone-beam CTs in 32 of 101 men to assess within-person variability of planned and delivered TD in a longitudinal analysis.

RESULTS

The median planned mTD for short course RT was 0.57 Gy (range 0.06-14.37 Gy) and 0.81 Gy (range 0.36-10.80 Gy) for long course RT. The median planned mTD was similar to the median delivered mTD in the 32 men analysed over the entire course of RT (p=0.84). The mTD did not change significantly over time of planning and delivering RT. The variation in proximity between testes and planning target volume (PTV) was related to within-person variability of mTD in men on the 50th and 75th percentile of mTD and as expected the absolute difference between planned and delivered mTD increased with higher mTD.

CONCLUSION

Testicular doses calculated based on plan-CT are an accurate estimation of delivered TD based on repeated cone beam (CB)CT. The within-person variability of TD is related to variation in proximity between testes and PTV in men with moderate to high TD.

[Sexual functions after treatment for rectal cancer: impact of doses in autonomic pelvic nerves]

PURPOSE

Prospective evaluation of sexual function after treatment of rectal cancer and identification of predictive factors.

PATIENTS AND METHODS

Thirty-three patients were treated with curative intent by chemoradiation and surgery for localized rectal adenocarcinoma. Sexual toxicity was assessed four times (before treatment and at 2, 6 and 12 months) using validated questionnaires: QLQ C30 and EORTC CR38 for all, simplified IIEF for men and FSFI for women. A correlation was sought between the toxicity and clinical and dosimetric parameters by Fisher and Mann-Whitney tests.

RESULTS

In men, erections and sexual satisfaction decreased significantly from the acute phase and then stabilized (respective scores of 84.5 and 86/100 in the initial phase, 66 and 70.4 at the end of radiotherapy, 70 and 70 at 6 months and 68.5 and 70 at 12 months). For women, the changes were not significant. This study confirms some risk factors for sexual toxicity already mentioned (original function, age, tumor volume) and highlights new (dose to the seminal vesicles and above all, doses to pelvic autonomic plexus).

CONCLUSION

Sexual effects of combined treatment of rectal cancer have only recently been described but remain undervalued and poorly understood. The impact of the autonomic pelvic plexus doses is a completely new data that could be extended in the development of intensity-modulated radiotherapy.

Hypofractionated passively scattered proton radiotherapy for low- and intermediate-risk prostate cancer is not associated with post-treatment testosterone suppression

Background.

To investigate post-treatment changes in serum testosterone in low- and intermediate-risk prostate cancer patients treated with hypofractionated passively scattered proton radiotherapy.

Material and methods.

Between April 2008 and October 2011, 228 patients with low- and intermediate-risk prostate cancer were enrolled into an institutional review board-approved prospective protocol. Patients received doses ranging from 70 Cobalt Gray Equivalent (CGE) to 72.5 CGE at 2.5 CGE per fraction using passively scattered protons. Three patients were excluded for receiving androgen deprivation therapy (n = 2) or testosterone supplementation (n = 1) before radiation. Of the remaining 226 patients, pretreatment serum testosterone levels were available for 217. Of these patients, post-treatment serum testosterone levels were available for 207 in the final week of treatment, 165 at the six-month follow-up, and 116 at the 12-month follow-up. The post-treatment testosterone levels were compared with the pretreatment levels using Wilcoxon's signed-rank test for matched pairs.

Results.

The median pretreatment serum testosterone level was 367.7 ng/dl (12.8 nmol/l). The median changes in post-treatment testosterone value were as follows: +3.0 ng/dl (+0.1 nmol/l) at treatment completion; +6.0 ng/dl (+0.2 nmol/l) at six months after treatment; and +5.0 ng/dl (0.2 nmol/l) at 12 months after treatment. None of these changes were statistically significant.

Conclusion.

Patients with low- and intermediate-risk prostate cancer treated with hypofractionated passively scattered proton radiotherapy do not experience testosterone suppression. Our findings are consistent with physical measurements demonstrating that proton radiotherapy is associated with less scatter radiation exposure to tissues beyond the beam paths compared with intensity-modulated photon radiotherapy.

Interval between Surgery and Radiation Therapy Is an Important Prognostic Factor in Treatment of Rectal Cancer

Purpose

The purpose of this study is to evaluate survival and prognostic factors for rectal cancer, including interval between surgery and radiation therapy after surgery, radiation therapy, and chemotherapy.

Materials and Methods

We conducted a retrospective study of 153 patients with rectal cancer who were treated with surgery, radiotherapy with/without chemotherapy at Keimyung University Dongsan Medical Center from January, 1988 to December, 2005. The study included 89 males and 64 females, with a median age of 56 years (range, 23 to 81 years). Tumor, node and metastasis (TNM) was I in 23 patients, II in 39, and III in 91. Radiation therapy was performed on pelvic fields using a median dose of 54 Gy five days per week, 1.8 Gy once per day. Ninety two patients were treated with radiotherapy, 43 with concurrent chemo-radiation therapy and 18 with sequential therapy after surgery. The median follow-up period was 52 months (range, 4 to 272 months). The interval between surgery and radiation was 1-25 weeks (median, 5 weeks).

Results

Two-year and five-year overall survival rate was 64.7% and 46.4%, respectively. Two-year and five-year disease-free-survival (DFS) rate was 58.6% and 43.1%, respectively. Median DFS was 39 months. Loco-regional failure was evident in 10.5% of patients, 8.4% had distant metastasis, and 9.2% had both. In multivariate analysis, TNM stage and interval between surgery and radiation therapy (≤5 weeks vs. >5 weeks; 95% confidence interval, 1.276 to 2.877; hazard ratio, 1.916; p=0.002) were significant prognostic factors of DFS.

Conclusion

Survival rates for rectal cancer after surgery, chemotherapy, and radiation therapy were similar to those reported in previous studies. Starting radiation therapy as soon as possible after surgery, especially within the first five weeks after surgery, is suggested.

Low incidence of new biochemical and clinical hypogonadism following hypofractionated stereotactic body radiation therapy (SBRT) monotherapy for low- to intermediate-risk prostate cancer

Background

The CyberKnife is an appealing delivery system for hypofractionated stereotactic body radiation therapy (SBRT) because of its ability to deliver highly conformal radiation therapy to moving targets. This conformity is achieved via 100s of non-coplanar radiation beams, which could potentially increase transitory testicular irradiation and result in post-therapy hypogonadism. We report on our early experience with CyberKnife SBRT for low- to intermediate-risk prostate cancer patients and assess the rate of inducing biochemical and clinical hypogonadism.

Methods

Twenty-six patients were treated with hypofractionated SBRT to a dose of 36.25 Gy in 5 fractions. All patients had histologically confirmed low- to intermediate-risk prostate adenocarcinoma (clinical stage ≤ T2b, Gleason score ≤ 7, PSA ≤ 20 ng/ml). PSA and total testosterone levels were obtained pre-treatment, 1 month post-treatment and every 3 months thereafter, for 1 year. Biochemical hypogonadism was defined as a total serum testosterone level below 8 nmol/L. Urinary and gastrointestinal toxicity was assessed using Common Toxicity Criteria v3; quality of life was assessed using the American Urological Association Symptom Score, Sexual Health Inventory for Men and Expanded Prostate Cancer Index Composite questionnaires.

Results

All 26 patients completed the treatment with a median 15 months (range, 13-19 months) follow-up. Median pre-treatment PSA was 5.75 ng/ml (range, 2.3-10.3 ng/ml), and a decrease to a median of 0.7 ng/ml (range, 0.2-1.8 ng/ml) was observed by one year post-treatment. The median pre-treatment total serum testosterone level was 13.81 nmol/L (range, 5.55 - 39.87 nmol/L). Post-treatment testosterone levels slowly decreased with the median value at one year follow-up of 10.53 nmol/L, significantly lower than the pre-treatment value (p < 0.013). The median absolute fall was 3.28 nmol/L and the median percent fall was 23.75%. There was no increase in biochemical hypogonadism at one year post-treatment. Average EPIC sexual and hormonal scores were not significantly changed by one year post-treatment.

Conclusions

Hypofractionated SBRT offers the radiobiological benefit of a large fraction size and is well-tolerated by men with low- to intermediate-risk prostate cancer. Early results are encouraging with an excellent biochemical response. The rate of new biochemical and clinical hypogonadism was low one year after treatment.