Radiation therapy in patients with inflammatory bowel disease and colorectal cancer: risks and benefits

PURPOSE

The effects of radiotherapy are debated in inflammatory bowel disease (IBD). We examined IBD patients with colorectal cancer (CRC) and compared those who underwent external beam radiation therapy (EBRT) to those who did not. We then compared those same patients treated with EBRT to similarly treated non-IBD patients to ascertain differences in toxicity and perioperative outcomes.

METHODS

Fifty-seven IBD patients with CRC received EBRT, of which 23 had perioperative follow-up and 15 had complete records. The 23 patients were compared to 229 IBD patients with CRC who did not receive EBRT. The 15 patients were matched, 1:2, to similarly treated non-IBD patients with CRC based on age (±5 years), treatment year (±1 year), BMI (±10 kg/m2), and clinical stage.

RESULTS

There was significantly more postoperative bleeding (5.3 % vs. 0 %, p < 0.01), wound dehiscence (3.5 % vs. 0 %, p < 0.01), and perineal infection (8.8 % vs. 1.3 %, p < 0.01) in IBD patients with EBRT compared to those without EBRT. IBD patients were significantly more likely to have grade 3 or higher lower GI toxicity (40 % vs. 7 %, p = 0.02) and wound dehiscence (36 % vs. 7 %, p = 0.02) than non-IBD patients, however without significant difference in bleeding, infection, ileus, or survival.

CONCLUSION

IBD patients with CRC who received EBRT were more likely than similar patients without EBRT to experience perioperative complications. These patients also experienced more lower GI toxicity than similarly treated non-IBD patients with CRC. The expected decrease in survival in IBD-associated CRC was not observed. Thus, EBRT may contribute to a survival benefit in this group.

ACR Appropriateness Criteria® rectal cancer: metastatic disease at presentation

The management of rectal cancer in patients with metastatic disease at presentation is highly variable. There are no phase III trials addressing therapeutic approaches, and the optimal sequencing of chemotherapy, radiation therapy, and surgery remains unresolved. Although chemoradiation is standard for patients with stage II/III rectal cancer, its role in the metastatic setting is controversial. Omitting chemoradiation may not be appropriate in all stage IV patients, particularly those with symptomatic primary tumors. Moreover, outcomes in this setting are vastly different, as some treatments carry the potential for cure in selected patients, while others are purely palliative. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application, by the panel, of a well-established consensus methodology (Modified Delphi) to rate the appropriateness of imaging and treatment procedures. In instances in which evidence is lacking or not definitive, expert opinion may be used as the basis for recommending imaging or treatment.

Evaluation of the current prostate cancer staging system based on cancer-specific mortality in the surveillance, epidemiology, and end results database

BACKGROUND

Prostate cancer is the most common noncutaneous malignancy diagnosed in men. From a large population-based database, this study aimed to report prostate cancer-specific mortality (PCSM) rates of men diagnosed with various presentations of prostate cancer and to examine the adequacy of the current American Joint Committee on Cancer (AJCC) staging system.

PATIENTS AND METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried for all patients diagnosed with prostate cancer from 1997 to 2005. PCSM was reported by the classification of extent of disease provided by the SEER database, for clinically staged and pathologically staged cohorts.

RESULTS

Using the cumulative incidence method, PCSM at 10 years for all patients (n = 354,326) was 5% for clinically localized (CL) lesions, 7% for T3aN0M0, 14% for T3bN0M0, 26% for T4N0M0, 27% for TanyN1M0, and 66% for TanyNanyM1. Within the pathologically staged subgroup (n = 108,135), PCSM at 10 years was 1% for CL lesions, 4% for T3aN0M0, 9% for T3bN0M0, 9% for T4N0M0, and 19% for TanyN1M0.

CONCLUSION

Staging of any disease site aims to accurately communicate, prognosticate, and guide management for that particular level of disease. Stage IV prostate cancer is a diverse group, with PCSM in the subgroups ranging from 9% to 68% in this study. Considering the favorable outcomes of those with T4 or N1 nonmetastatic prostate cancer relative to those with M1 disease, the authors propose that T4 or N1 M0 prostate cancer should be reclassified into a new stage IIIB and that patients with such disease should be offered curative-intent therapy whenever possible.

Brachytherapy boost in loco-regionally advanced nasopharyngeal carcinoma: a prospective randomized trial of the International Atomic Energy Agency

Abstact

Risk for developing myelodysplastic syndromes in prostate cancer patients definitively treated with radiation

BACKGROUND

Exposure to ionizing radiation has been linked to myelodysplastic syndromes (MDS); it is not clear whether therapeutic radiation doses used for prostate cancer pose an increased MDS risk.

METHODS

We performed a retrospective cohort study of prostate cancer patients diagnosed between 1986 and 2011 at Cleveland Clinic, comparing those who underwent definitive treatment with radical prostatectomy (RP) to radiotherapy either external beam radiotherapy (EBRT) or prostate interstitial brachytherapy (PI) and to population-based registries. Competing risk regression analyses were used to determine the cumulative risk of developing MDS. All statistical tests were two-sided.

RESULTS

Of 10924 patients, 5119 (47%) received radiation (n = 2183 [43%] in EBRT group and n = 2936 [57%] in PI group) and 5805 (53%) were treated with RP. Overall, 31 cases of MDS were observed, with age-adjusted incidence rates no higher than in population-based registries. In univariate analyses, advancing age (hazard ratio [HR] = 1.14; 95% confidence interval [CI] = 1.09 to 1.20; P < .001) and radiotherapy exposure (HR = 3.44; 95% CI = 1.41 to 8.37; P = .007) were statistically significantly associated with development of MDS. In multivariable analyses, although advanced age (HR = 1.13; 95% CI = 1.06 to 1.19; P < .001) remained statistically associated with MDS, radiation did not, although a small non-statistically significant trend existed for PI-treated patients. MDS rates were no higher than in population-based registries.

CONCLUSIONS

With relatively short follow-up, prostate cancer patients definitively treated with radiation did not appear to have a statistically increased risk of subsequent MDS.

Comparing outcomes and toxicities from intensity-modulated radiation therapy and three-dimensional conformal radiation therapy for anal cancer: Is one really better?

589

Background: Intensity-modulated radiation therapy (IMRT) has largely supplanted 3-dimensional conformal radiation (3D-CRT) for definitive treatment of anal cancer due to its decreased toxicity and potentially improved outcomes. Convincing data directly demonstrating its advantages, however, remain limited. We compared outcomes, acute, and post-treatment toxicity of patients with anal cancer treated with concurrent chemotherapy and IMRT vs. 3D-CRT. Methods: We performed a single institution retrospective review of patients treated with IMRT or 3D-CRT as part of definitive Mitomycin-C/5-FU based chemoradiation for anal cancer from January 2003-December 2012. Results: 61 and 104 patients received IMRT and 3D-CRT respectively. Overall, 92.7% had squamous cell carcinoma. The mean pelvic dose before boost was 48.3Gy and 44Gy for IMRT and 3D-CRT respectively. Complete response, partial response, and disease progression rates were similar (83.6%, 8.2%, 8.2% for IMRT; 85.6%, 6.7%, 7.7% for 3D-CRT; p = ns). There was no significant difference in overall survival (p = 0.971), event free survival (p = 0.900), and local or distant recurrence rates (p = 0.118, p = 0.373). IMRT caused significantly less acute grade 1-2 incontinence (p = 0.035), grade 3-4 pain (p = 0.033) and fatigue (p = 0.030). Patients receiving IMRT had significantly fewer post-treatment toxicities (p = 0.008), outperforming 3D-CRT in 7/8 toxicities reviewed. Though total length of treatment was comparable between IMRT and 3D-CRT (43.6 and 44.5 days), the IMRT group had fewer, shorter treatment breaks (p = ns). Conclusions: This report represents the largest series directly comparing concurrent chemotherapy with IMRT vs. 3D-CRT for definitive treatment of anal cancer. IMRT significantly reduced acute and post-treatment toxicities and allowed for safe and effective pelvic dose escalation.

Adjuvant chemoradiation to improve survival compared to adjuvant chemotherapy in selected patients with pancreatic cancer

330

Background: While surgery remains the only potential curative option for resectable pancreatic cancer, adjuvant therapy improves outcomes over surgery alone; however, adjuvant recommendations of chemotherapy vs chemoradiation remain controversial. We present outcomes comparing the two adjuvant treatments. Methods: In our single institution review, 343 patients (2000-2012) had pancreatoduodenectomy for pancreatic cancer. Medical oncology made adjuvant recommendations. Chemotherapy was gemcitabine or 5-FU and radiotherapy prescription was 45-54 Gy. Locoregional recurrences (LRR) were operative bed or regional nodal failures. Results: Median follow up and median survival (MS) for all patients was 17.5 and 19.5 mo respectively. 130 patients had resection alone (A), 84 had adjuvant chemotherapy (B), and 129 had adjuvant chemoradiation (C). MS for groups A, B, and C were 13, 23 and 26 mo respectively. Locoregional recurrence (LRR) was 60%, 63%, and 38% and distant failure was 64%, 65%, and 66% for groups A, B, and C respectively. Group C had significantly lower LRR compared to group B (p=0.01) however, survival between groups B and C was not statistically significant (p=0.23). Angiolymphatic invasion (ALI) and perineural invasion were correlated with LRR (p<0.01). Multivariable analysis showed LRR, laparoscopy, ALI, and the interaction term of LRR with surgical margin were significant predictors of survival (p<0.05). MS of patients with lymph node ratio (LNR) > 0.2 and LNR ≤ 0.2 was 18 and 27 mo respectively. Subgroup analysis showed survival advantages to adjuvant chemoradiation compared with adjuvant chemotherapy. R1 resections in groups B and C were 37% and 39% (p=ns) with MS of 16 vs 27 mo respectively (p=0.01). For patients with ≥ 8 LN dissected and LNR ≤ 0.2, MS was 24 vs 32 mo for groups B and C respectively (p=0.04). Conclusions: Adjuvant chemoradiation significantly decreases LRR in resected pancreatic cancer patients. Compared to adjuvant chemotherapy alone, adjuvant chemoradiation improved survival for patients with a 1) positive surgical margin and/or 2) LNR ≤ 0.2 with ≥ 8 LNs dissected.

Does up-front definitive surgical resection with delayed chemotherapy in patients with stage IV rectal cancer compromise overall survival?

586

Background: Definitive resection of the primary is frequently part of the management of patients (pts) with stage IV rectal cancer with good performance status and low volume of systemic metastases. It is unclear whether delaying systemic therapy for up front surgical management of the primary compromises overall survival (OS). Methods: Pts with metastatic rectal adenocarcinoma who received definitive surgical resection between 1998-2011 were identified in an IRB approved registry. The sequencing of CT and surgery, and the use of perioperative radiation therapy (RT), was at the discretion of treating physicians. Preoperative chemotherapy (Pre-CT) regimens included 5-fluorouracil (5-FU) +/- leukovorin (LV), capecitabine, 5-FU/LV/oxaliplatin +/- avastin, or 5-FU/LV/irinocetan. RT dose was typically 50.4 Gy. OS was measured from the date of diagnosis. Baseline variables were compared using the Chi-square and unpaired t-tests. OS was calculated using the Kaplan Meier method. Univariate (UVA) and multivariate analysis (MVA) were performed using Cox proportional hazards regression to identify variables associated with OS. Results: In this study of 115 pts, 75 (65%) were treated with pre-CT, while 40 (35%) were treated with up front surgery. Of the pts who received surgery up front, 3 (8%) received RT and of the pts who received pre-CT, 62 (83%) received RT. The cohort was predominantly male (70%) with a median age of 57, median KPS of 80, and median follow-up of 24.1 months. 94% of pts had T3/T4 tumors, 80% had N+ disease, and 33% had poorly differentiated tumors. Liver directed therapy (LDT) was performed in 61% of pts. There was no significant difference in OS (32.3 vs. 32 months; p = 0.24) between pts treated with pre-CT and those who received surgery up front, respectively. UVA demonstrated that pre-CT was not associated with OS (HR 1.26; p = 0.544). MVA demonstrated that pts with poorly differentiated tumors (HR 2.04; p = 0.007) and those that did not undergo LDT (HR 2.45; p = 0.001) had inferior survival. Conclusions: Delaying systemic chemotherapy in order to achieve local control with surgical resection up front does not appear to impact OS in pts with stage IV rectal cancer.

Do inflammatory bowel disease patients experience more toxicity after radiotherapy for colorectal and anal cancer?

570

Background: Despite potential oncologic gains from using radiotherapy in patients with inflammatory bowel disease (IBD), it has historically been contraindicated due to increased acute gastrointestinal (GI) toxicity. Yet recent published literature is mixed with regards to toxicity outcomes in these patients. In this study, we examine GI, genitourinary (GU), and skin toxicity in IBD patients compared to non-IBD patients both treated with external beam radiation therapy (EBRT) for anal or colorectal cancer (CRC). Methods: Anal and CRC patients who received EBRT were included in this single institutional IRB-approved study. 15 IBD patients and 30 non-IBD patients were matched 1:2 based on age (±5 years), treatment year (±1 year), BMI (±10 kg/m2), and clinical stage. No IBD patients had documented active disease at the time of treatment. All patients had a pathologic diagnosis of anal or CRC and received EBRT either neoadjuvantly or adjuvantly. Acute toxicity occurred within 100 days of EBRT. Data was collected via retrospective review of the treatment charts. Results: All patients received radiation doses between 45-52 Gy in 1.8Gy/fx or 2Gy/fx, delivered using AP/PA, IMRT, 3-field, or 4-field plans. There was no difference in the rate of grade 3 (20% vs 7%, p=0.19) or grade 4 (7% vs 0%, p=0.13) lower GI toxicity. There was also no difference in the incidence of GU (47% vs 30%, p=0.37), upper GI (60% vs 33.3%, p=0.08), or skin toxicity (40% vs 64%, p=0.17). Post-operatively, IBD patients had a significantly higher rate of wound dehiscence (35.7% vs 7.1%, p=0.02); however, there was no difference in the rate of bleeding (29% vs 18%, p=0.43), infection (50% vs 32%, p=0.50), or ileus (36% vs 11%, p=0.06). Conclusions: IBD patients with anal or CRC who received EBRT neoadjuvantly or adjuvantly did not experience more acute GI, GU, or skin toxicity than matched non-IBD patients with similar treatment. Post-operatively, IBD patients were more likely to have wound dehiscence, but were not more likely to have bleeding, infection, or ileus.

ACR Appropriateness Criteria®-Anal Cancer

The management of anal cancer is driven by randomized and nonrandomized clinical trials. However, trials may present conflicting conclusions. Furthermore, different clinical situations may not be addressed in certain trials because of eligibility inclusion criteria. Although prospective studies point to the use of definitive 5-fluorouracil and mitomycin C-based chemoradiation as a standard, some areas remain that are not well defined. In particular, management of very early stage disease, radiation dose, and the use of intensity-modulated radiation therapy remain unaddressed by phase III studies. The American College of Radiology (ACR) Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Calculating isotope concentrations using different schemes of dispersion parameters

The investigated work aims to calculate the concentration of different isotopes through short downwind distances. A theoretical model was designed to calculate the isotope concentration in the wind. The mathematical calculation depends on wind speed, decay distance and the dilution factor to get the concentration of isotopes ((131)I, (133)I, (135)I and (137)Cs) detected in wind at different distances from a nuclear power station. There is a good agreement between the calculated and observed concentrations of (131)I, (133)I, (135)I and (137)Cs.