Radiotherapy and short-term androgen deprivation for localized prostate cancer

BACKGROUND

It is not known whether short-term androgen-deprivation therapy (ADT) before and during radiotherapy improves cancer control and overall survival among patients with early, localized prostate adenocarcinoma.

METHODS

From 1994 through 2001, we randomly assigned 1979 eligible patients with stage T1b, T1c, T2a, or T2b prostate adenocarcinoma and a prostate-specific antigen (PSA) level of 20 ng per milliliter or less to radiotherapy alone (992 patients) or radiotherapy with 4 months of total androgen suppression starting 2 months before radiotherapy (radiotherapy plus short-term ADT, 987 patients). The primary end point was overall survival. Secondary end points included disease-specific mortality, distant metastases, biochemical failure (an increasing level of PSA), and the rate of positive findings on repeat prostate biopsy at 2 years.

RESULTS

The median follow-up period was 9.1 years. The 10-year rate of overall survival was 62% among patients receiving radiotherapy plus short-term ADT (the combined-therapy group), as compared with 57% among patients receiving radiotherapy alone (hazard ratio for death with radiotherapy alone, 1.17; P=0.03). The addition of short-term ADT was associated with a decrease in the 10-year disease-specific mortality from 8% to 4% (hazard ratio for radiotherapy alone, 1.87; P=0.001). Biochemical failure, distant metastases, and the rate of positive findings on repeat prostate biopsy at 2 years were significantly improved with radiotherapy plus short-term ADT. Acute and late radiation-induced toxic effects were similar in the two groups. The incidence of grade 3 or higher hormone-related toxic effects was less than 5%. Reanalysis according to risk showed reductions in overall and disease-specific mortality primarily among intermediate-risk patients, with no significant reductions among low-risk patients.

CONCLUSIONS

Among patients with stage T1b, T1c, T2a, or T2b prostate adenocarcinoma and a PSA level of 20 ng per milliliter or less, the use of short-term ADT for 4 months before and during radiotherapy was associated with significantly decreased disease-specific mortality and increased overall survival. According to post hoc risk analysis, the benefit was mainly seen in intermediate-risk, but not low-risk, men. (Funded by the National Cancer Institute; RTOG 94-08 ClinicalTrials.gov number, NCT00002597.).

Randomized, double-blinded, placebo-controlled crossover trial of treating erectile dysfunction with sildenafil after radiotherapy and short-term androgen deprivation therapy: results of RTOG 0215

INTRODUCTION

Erectile dysfunction (ED) may be the most commonly observed adverse event (AE) associated with the combination of radiation therapy (RT) and androgen deprivation therapy (ADT). A significant number of men are trying phosphodiesterase type 5 inhibitors (PDE5s) such as sildenafil to treat ED, yet sildenafil studies to date shed little light on the response to ED after ADT.

AIM

The purpose of this trial was to evaluate sildenafil in the treatment of ED in prostate cancer patients previously treated with external beam RT and neoadjuvant and concurrent ADT.

METHODS

  In this randomized, double-blinded crossover trial, eligible patients received RT/ADT for intermediate risk prostate cancer and currently had ED as defined by the International Index of Erectile Function (IIEF). Patients were randomized to 12 weeks of sildenafil or placebo followed by 1 week of no treatment then 12 weeks of the alternative. Treatment differences were evaluated using a marginal model for binary crossover data.

MAIN OUTCOME MEASURES

The primary end point was improved erectile function, as measured by the IIEF.

RESULTS

The study accrued 115 patients and 61 (55%) completed all three IIEF assessments. Sildenafil effect was significant (P = 0.009) with a difference in probabilities of erectile response of 0.17 (95% confidence interval: 0.06, 0.29), and 0.21 (0.06, 0.38) for patients receiving ≤ 120 days of ADT. However, as few as 21% of patients had a treatment-specific response, only improving during sildenafil but not during the placebo phase.

CONCLUSIONS

This is the first controlled trial to suggest a positive sildenafil response for ED treatment in patients previously treated with RT/ADT, however, only a minority of patients responded to treatment. ADT duration may be associated with response and requires further study. The overall low response rate suggests the need for study of additional or preventative strategies for ED after RT/ADT for prostate cancer.

Two-year outcomes of RTOG 0529: A phase II evaluation of dose-painted IMRT in combination with 5-fluorouracil and mitomycin-C for the reduction of acute morbidity in carcinoma of the anal canal

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Background: 5-Fluorouracil (5FU) and mitomycin-C (MMC) chemoradiation for anal cancer is associated with high rates of acute morbidity. We have previously shown that dose-painted IMRT (DP-IMRT) significantly reduces grade 3+ GI and dermatologic acute toxicity, as compared to the RTOG 9811 5FU/MMC arm, which used non-conformal radiation techniques. We now report on the two-year outcomes of this DP-IMRT approach.

Methods: T2-4N0-3M0 anal canal cancers received 5FU (1,000 mg/m2/day 96 hour infusion) and MMC (10 mg/m2 bolus) days 1 and 29 of DP-IMRT prescribed as follows - T2N0: 42 Gy elective nodal and 50.4 Gy anal tumor planning target volumes (PTVs), 28 fractions; T3-4N0-3: 45 Gy elective nodal, 50.4 Gy ≤ 3 cm and 54 Gy > 3 cm metastatic nodal and 54 Gy anal tumor PTVs, 30 fractions. The following two-year outcomes were assessed: local-regional (LRF) and colostomy failures (CF) using the cumulative incidence method, and disease-free (DFS), overall (OS) and colostomy-free survivals (CFS) using the Kaplan-Meier method.

Results: Of 63 accrued patients, 52 were analyzable. Median age was 58 years; 81% female; 54% stage II; 25% IIIA; 21% IIIB. Median follow-up was 23.2 months (0.2-33). Two-year LRF, CF, DFS and 95% confidence intervals are 20% (9%, 31%), 8% (0.4%, 15%) and 77% (62%, 86%), respectively. The causes of death for the 7 patients that died are: anal cancer in 5, morbidity in one and second primary outside the radiation field in one. Two-year comparison data from the RTOG 9811 5FU/MMC arm are shown in the table below.

Conclusions: DP-IMRT with 5FU/MMC for the treatment of anal canal cancer yields similar two-year outcomes as the RTOG 9811 conventional radiation, 5FU/MMC arm. Because of the associated acute toxicity sparing, DP-IMRT will be used as the platform, and may allow for radiation dose escalation, in future RTOG anal canal trials. Supported by RTOG U10 CA21661, CCOP U10 CA3742 and ATC U24 CA 81647 NCI grants.

[Table: see text]

No significant financial relationships to disclose.

Octreotide acetate in prevention of chemoradiation-induced diarrhea in anorectal cancer: randomized RTOG trial 0315

BACKGROUND

In anorectal cancer patients, an acute side effect of chemoradiotherapy is gastrointestinal toxicity, which often impedes treatment delivery. Based on previous trials, octreotide acetate is widely recommended for the control of chemotherapy-induced diarrhea. However, the effectiveness of octreotide in preventing or controlling radiation- and chemoradiation-induced diarrhea is not known.

METHODS

A randomized, double-blinded, placebo-controlled trial was designed to determine the efficacy of long-acting octreotide acetate (LAO) in preventing the onset of acute diarrhea in patients undergoing chemoradiation therapy for rectal or anal cancer. Between 4 and 7 days before the start of radiation therapy, patients received a 30-mg dose of LAO (109 patients) or placebo (106 patients) via intramuscular injection. A second dose was given on day 22 (+/-3 days) of radiation treatment. A total of 215 patients were included in the final analysis. The primary endpoint was the incidence of grade 2-4 acute diarrhea; secondary endpoints included treatment compliance, medical resource utilization, patient-reported bowel function, and quality of life (QoL). Statistical tests were one- or two-sided, as specified.

RESULTS

After a median follow-up time of 9.64 months, incidence rates of grades 2-4 acute diarrhea were similar in both groups (49% placebo vs 44% LAO; P = .21). No statistically significant treatment differences in chemotherapy or radiation delivery, medical resource utilization, patient-reported bowel function, or QoL were observed.

CONCLUSION

In this study, the prophylactic use of LAO did not prevent the incidence or reduce the severity of diarrhea and had no notable impact on patient-reported bowel function or QoL.

Survival outcomes with the use of surgery in limited-stage small cell lung cancer: should its role be re-evaluated?

BACKGROUND

Although chemotherapy and radiation therapy currently are recommended in limited-stage small cell lung cancer (L-SCLC), several small series have reported favorable survival outcomes in patients who underwent surgical resection. The authors of this report used a US population-based database to determine survival outcomes of patients who underwent surgery.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) registry was used to identify patients who were diagnosed with L-SCLC between 1988 and 2002 coded by SEER as localized disease (T1-T2Nx-N0) or regional disease (T3-T4Nx-N0). Kaplan-Meier and Cox regression analyses were used to compare overall survival (OS) for all patients.

RESULTS

In total, 14,179 patients were identified, including 863 patients who underwent surgical resection. Surgery was associated more commonly with T1/T2 disease (P < .001). Surgery was associated with improved survival for both localized disease and regional disease with improvements in median survival from 15 months to 42 months (P < .001) and from 12 months to 22 months (P < .001), respectively. Lobectomy was associated with the best outcome (P < .001). Patients with localized disease who underwent lobectomy with had a median survival of 65 months and a 5-year OS rate of 52.6%; whereas patients who had regional disease had a median survival of 25 months and a 5-year OS rate of 31.8%. On multivariate analysis, the benefit of surgery varied in a time-dependant fashion. However, the benefit of lobectomy remained across all time intervals (P = .002).

CONCLUSIONS

The use of surgery, and particularly lobectomy, in selected patients with L-SCLC was associated with improved survival outcomes. Future prospective studies should consider the role of surgery as part of the multimodality management of this disease.

MDM2 and Ki-67 predict for distant metastasis and mortality in men treated with radiotherapy and androgen deprivation for prostate cancer: RTOG 92-02

PURPOSE MDM2 regulates p53, which controls cell cycle arrest and apoptosis. Both proteins, along with Ki-67, which is an established strong determinant of metastasis, have shown promise in predicting the outcome of men treated with radiation therapy (RT) with or without short-term androgen deprivation (STAD). This report compares the utility of abnormal expression of these biomarkers in estimating progression in a cohort of men treated on RTOG 92-02. PATIENTS AND METHODS Adequate tissue for immunohistochemistry was available for p53, Ki-67, and MDM2 analyses in 478 patient cases. The percentage of tumor nuclei staining positive (PSP) was quantified manually or by image analysis, and the per-sample mean intensity score (MIS) was quantified by image analysis. Cox regression models were used to estimate overall mortality (OM), and Fine and Gray's regressions were applied to the end points of distant metastasis (DM) and cause-specific mortality (CSM). Results In multivariate analyses that adjusted for all markers and treatment covariates, MDM2 overexpression was significantly related to DM (P = .02) and OM (P = .003), and Ki-67 overexpression was significantly related to DM (P < .0001), CSM (P = .0007), and OM (P = .01). P53 overexpression was significantly related to OM (P = .02). When considered in combination, the overexpression of both Ki-67 and MDM2 at high levels was associated with significantly increased failure rates for all end points (P < .001 for DM, CSM, and OM). CONCLUSION Combined MDM2 and Ki-67 expression levels were independently related to distant metastasis and mortality and, if validated, could be considered for risk stratification of patients with prostate cancer in clinical trials.

Overall survival using local excision techniques with and without radiation compared with APR for stage I rectal cancer: A SEER based analysis

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Background: The standard of care for Stage I rectal cancer is radical resection. Increasingly, local therapies have been used to decrease morbidity and preserve sphincter control. Due to increased risk of local recurrence with less radical surgery, patients often receive adjuvant radiation. This analysis compares the outcomes of sphincter sparing treatment with radical surgery in Stage I rectal cancer. Methods: Using the Surveillance, Epidemiology and End-Results (SEER) registry, we performed a query of patients with Stage T1–2N0 (T=4 cm or less) rectal adenocarcinoma between 1988 and 2003 who were treated with either local excision alone (LE), local excision followed by radiotherapy (LE+RT) or abdominoperineal resection (APR). APR was selected as comparison group to select for a similar cohort of patients with distal tumors that would be eligible for LE. Kaplan-Meier analysis was performed to compare overall survival for patients receiving radical surgery versus local therapy. Subgroup survival analysis was performed by T-stage (T1 vs T2). Results: 2,144 patients were identified: 744 were treated with LE alone, 197 underwent LE+RT, and 1203 underwent APR. Patients undergoing LE ± RT had a median survival (MS) of 131 vs 121 months in the APR group (p=0.574). When comparing LE vs LE+RT, there was no difference in MS for the whole cohort (134 vs 108 months, p=0.39). However, on subgroup analysis there was a significant survival benefit in favor of LE+RT for T2N0 only (104 vs 74 months, p=0.048). For T1N0, the MS for LE+RT was 161 vs 147 months for LE (p=0.621). Comparing with APR, patients undergoing LE+RT had a MS of 108 vs 121 months in the APR group (p=0.684). For T1N0, the MS for LE+RT was 161 vs 153 months for APR (p=0.62). For T2N0 patients, the MS for LE+RT was 104 vs 114 months for APR (p=0.726). Conclusions: According to this analysis, there was no statistical difference in survival for patients with Stage I rectal carcinoma undergoing APR versus LE+RT. Selected patients with T1N0 may undergo local excision alone. However, patients with T2N0 disease should undergo adjuvant radiation after local excision. The risks and benefits of these treatment strategies should be weighed and treatment should be individualized.

No significant financial relationships to disclose.

Radical prostatectomy in clinically localized prostate cancer—The risk of extraprostatic spread by NCCN risk group and its implications for adjuvant therapy: An analysis of 23,988 patients

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Background: Swanson et al recently reported an update of SWOG 8794 (ASTRO 2008, oral presentation) revealing a 10% absolute overall survival benefit at 15 years with adjuvant radiation therapy for patients with extraprostatic extension (EPE) or positive margins after radical prostatectomy (RP). In this population based analysis, we analyze and report on the pathologic rates of EPE or positive margins in clinically localized prostate cancer as well as how often these patients have received adjuvant radiation therapy. Methods: The Surveillance, Epidemiology and End Results (SEER) registry was used to identify patients between 2004–2005 with clinically staged T1-T2c prostate cancer who underwent RP. Patients were stratified using NCCN risk groups into low (T1c- T2a, PSA less than 10ng/ml, Gleason 2–6), intermediate (T2b, PSA 10–20ng/ml, Gleason 7), and high (T2c, PSA greater than 20ng/ml, Gleason 8–10). Results: 23,988 patients were identified: 6,314 in the NCCN low risk group (LR), 12,052 in the NCCN intermediate risk group (IR), and 5,622 in the NCCN high risk group (HR). Overall, 68.2% of patients had organ-confined disease with negative margins. However, the risk of EPE or positive margins increased with the NCCN risk group, PSA value, and Gleason score (see table ). Of those who met criteria for adjuvant radiation, 11.9% received the treatment: 4.7% of the LR group, 9.2% of the IR group and 18.9% of the HR group. Conclusions: This is, to our knowledge, the largest reported multi-institutional surgical series of clinically localized prostate cancer. Patients can use this data to be counseled on their risk of requiring adjuvant radiation based on their pre-treatment parameters. This data also reveals that nearly one third of all patients met the indications for adjuvant radiation, but only a small percentage of them received this treatment.

[Table: see text]

No significant financial relationships to disclose.

Utilization of radiation therapy in early-stage Hodgkin disease and its impact on survival

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Background: Despite numerous randomized trials confirming the benefit of consolidation radiation therapy (RT) in the management of early stage Hodgkin disease (HD), utilization of RT in this setting remains variable. We performed a population-based analysis to assess the utilization of RT and its impact on overall and cause specific survival. Methods: The surveillance, epidemiology and end results (SEER) registry was used to identify patients aged 15–75 years diagnosed between 1990–2004 with early stage (stage I-IIA/B) HD, excluding nodular lymphocyte predominant HD. Kaplan-Meier analysis was performed to evaluate the effect of RT on overall survival (OS) and cause-specific survival (CSS). Subgroup survival analyses were also performed by era of treatment (1990–1997 and 1998–2004), sex, and patient age (<30, 30–50, and >50 years). Results: A total of 9729 patients met inclusion criteria. Median age of all patients was 34 years. The majority (71.3%) had nodular sclerosis (NS) type HD. By clinical stage, 3399 (34.9%) were stage I, and 6330 (65.1%) were stage II. 5352 patients (55%) received RT. RT was more likely to be employed during the early era of treatment, in younger patients, females, non-Blacks, and in NS, mixed cellularity and lymphocyte-rich HD. For the entire cohort, RT was associated with a significant (p<0.001) improvement in OS and CSS (hazard ratio of 0.537 and 0.437, respectively). The benefit of RT for OS and CSS remained significant for all subgroups analyzed including the era of treatment, sex, and age (p≤0.001). Conclusions: In this large population-based series of early stage HD patients, the use of RT is associated with a significant OS and CSS benefit across all subgroups. Current efforts in clinical trials have aimed at decreasing the utilization of RT among this patient population. This shift in practice is reflected in the data presented here. The omission of RT from the treatment paradigm, however, appears to be related with diminished survival.

No significant financial relationships to disclose.