Bayesian network structure for predicting local tumor recurrence in rectal cancer patients treated with neoadjuvant chemoradiation followed by surgery.

Background and Purpose: Tumor recurrence, a characteristic of malignant tumors, is the biggest concern for rectal cancer survivors. The epidemiology of the disease calls for a pressing need to improve healthcare quality and patient outcomes. Prediction models such as Bayesian networks, which can probabilistically reason under uncertainty, could assist caregivers with patient management. However, some concerns are associated with the standard approaches to developing these structures in medicine. Therefore, this study aims to compare Bayesian network structures that stem from these two techniques. Patients and Methods: A retrospective analysis was performed on 6754 locally advanced rectal cancer (LARC) patients enrolled in 14 international clinical trials. Local tumor recurrence at 2, 3, and 5-years was defined as the endpoints of interest. Five rectal cancer treating physicians from three countries elicited the expert structure. The algorithmic structure was inferred from the data with the hill-climbing algorithm. Structural performance was assessed with calibration plots and area under the curve values. Results: The area under the curve for the expert structure on the training and validation data was above 0.9 and 0.8, respectively, for all the time points. However, the algorithmic structure had superior predictive performance over the expert structure for all time points of interest. Conclusion: We have developed and internally validated a Bayesian networks structure from experts' opinions, which can predict the risk of a LARC patient developing a tumor recurrence at 2, 3, and 5 years. Our result shows that the algorithmic-based structures are more performant and less interpretable than expert-based structures.

Treatment outcomes and prognostic factors after chemoradiotherapy for anal cancer.

BACKGROUND: Squamous cell carcinoma of the anus (SCCA) is a rare malignancy with rising incidence, associated with human papilloma virus (HPV). Chemoradiotherapy (CRT) is the preferred treatment. The purpose was to investigate treatment failure, survival and prognostic factors after CRT. MATERIAL AND METHODS: In this prospective observational study from a large regional centre, 141 patients were included from 2013 to 2017, and 132 were eligible for analysis. The main inclusion criteria were SCCA, planned radiotherapy, and performance status (ECOG) ≤2. Patient characteristics, disease stage, treatment, and treatment response were prospectively registered. Disease-free survival (DFS), overall survival (OS), and locoregional treatment failure after CRT were analysed. Hazard ratios (HRs) were estimated with Cox`s proportional hazards model. RESULTS: Median follow-up was 54 (range 6-71) months. Eighteen patients (14%) had treatment failures after CRT; of these 10 (8%) had residual tumour, and 8 (6%) relapse as first failure. The first treatment failure was locoregional (11 patients), distant (5 patients), and both (2 patients). Salvage abdomino-perineal resection was performed in 10 patients, 2 had resections of metastases, and 3 both. DFS was 85% at 3 years and 78% at 5 years. OS was 93% at 3 years and 86% at 5 years. In analyses adjusted for age and gender, HPV negative tumours (HR 2.5, p = 0.024), N3 disease (HR 2.6, p = 0.024), and tumour size ≥4 cm (HR 2.4, p = 0.038) were negative prognostic factors for DFS. CONCLUSION: State-of-the-art chemoradiotherapy for SCCA resulted in excellent outcomes, and improved survival compared with previous national data, with <15% treatment failures and a 3-year DFS of >80%.

Preoperative radiotherapy or chemoradiotherapy in rectal cancer - Is survival improved? An update of the "Nordic" LARC study in non-resectable cancers.

The randomized "Nordic" LARC study compared preoperative long-course radiotherapy alone (RT) or with chemotherapy (CRT) in the most locally advanced/ugly rectal cancers. Despite significantly better local control in the CRT group, no overall survival benefit was seen after 10 years follow-up. The relations between local control and survival are discussed.

Nationwide improvement of rectal cancer treatment outcomes in Norway, 1993-2010.

BACKGROUND: The Norwegian Rectal Cancer Project was initated in 1993 with the aims of improving surgery, decreasing local recurrence rates, improving survival, and establishing a national rectal cancer registry. Here we present results from the Norwegian Colorectal Cancer Registry (NCCR) from 1993 to 2010. MATERIAL AND METHODS: A total of 15 193 patients were diagnosed with rectal cancer in Norway 1993-2010, and were registered with clinical data regarding diagnosis, treatment, locoregional recurrences and distant metastases. Of these, 10 796 with non-metastatic disease underwent tumour resection. The results were stratified into five time periods, and the treatment outcomes were compared. Recurrence rates are presented for the 9785 patients who underwent curative major resection (R0/R1). RESULTS: Among all 15 193 patients, relative five-year survival increased from 54.1% in 1993-1997 to 63.4% in 2007-2010 (p < 0.001). Among the 10 796 patients with stage I-III disease who underwent tumour resection, from 1993-1997 to 2007-2010, relative five-year survival improved from 71.2% to 80.6% (p < 0.001). An increasing proportion of these patients underwent surgery at large-volume hospitals; and 30- and 100-day mortality rates, respectively, decreased from 3.0% to 1.4% (p < 0.001) and from 5.1% to 3.0% (p < 0.011). Use of preoperative chemoradiotherapy increased from 6.5% in 1993 to 39.0% in 2010 (p < 0.001). Estimated local recurrence rate after major resection (R0/R1) decreased from 14.5% in 1993-1997 to 5.0% in 2007-2009 (p < 0.001), and distant recurrence rate decreased from 26.0% to 20.2% (p < 0.001). CONCLUSION: Long-term outcomes from a national population-based rectal cancer registry are presented. Improvements in rectal cancer treatment have led to decreased recurrence rates of 5% and increased survival on a national level.

Reirradiation of locally recurrent rectal cancer: a systematic review.

BACKGROUND: Many patients with rectal cancer receive radiotherapy as a component of primary multimodality treatment. Although local recurrence is infrequent, reirradiation may be needed to improve resectability and outcomes. This systematic review investigated the effects of reirradiation in terms of feasibility, toxicity, and long-term outcomes. METHODS: A Medline, Embase and Cochrane search resulted in 353 titles/abstracts. Ten publications describing seven prospective or retrospective studies were included, presenting results of 375 patients reirradiated for rectal cancer. RESULTS: Median initial radiation dose was 50.4Gy, median 8-30months before reirradiation. Reirradiation was mostly administered using hyperfractionated (1.2-1.5Gy twice-daily) or 1.8Gy once-daily chemoradiotherapy. Median total dose was 30-40Gy to the gross tumour volume with 2-4cm margins. Median survival was 39-60months in resected patients and 12-16months in palliative patients. Good symptomatic relief was reported in 82-100%. Acute toxicity with diarrhoea was reported in 9-20%, late toxicity was insufficiently reported. CONCLUSIONS: Reirradiation of rectal cancer to limited volumes is feasible. When curative resection is possible, the goal is radical resection and long-term survival, and hyperfractionated chemoradiotherapy should be preferred to limit late toxicity. Reirradiation yielded good symptomatic relief in palliative treatment.

Integrated peripheral boost in preoperative radiotherapy for the locally most advanced non-resectable rectal cancer patients.

BACKGROUND AND PURPOSE: Few studies have explored the potential clinical advantages of dose escalation and integrated boosts for patients with non-resectable locally advanced rectal cancer. The possibility of escalating dose to non-resectable regions in these patients was the aim of this study. PATIENTS AND METHODS: Seven patients with locally very advanced rectal tumours (sacrum overgrowth or growth into pelvic side walls) were evaluated. Intensity modulated photon and pencil beam scanning proton plans with simultaneously integrated boosts (45 Gy to elective lymph nodes, 50 Gy to tumour and 62.5 Gy to boost area in 25 fractions) were compared. RESULTS: Target coverage was achieved with both photon and proton plans. Estimated risks of acute side effects put the two patients with the largest tumours at unacceptable risk for intestinal toxicity, regardless of modality. The remaining five patients had beneficial sparing of dose to the small intestine with protons. CONCLUSIONS: Adding boost to areas where rectal tumours infiltrate adjacent non-resectable organs is an attractive option which appears possible using both photon and proton irradiation. Proton plans reduced dose to organs at risk. Integrated peripheral boosts should be considered more frequently in these very advanced tumours.

Health-related quality of life (HRQoL) after multimodal treatment for primarily non-resectable rectal cancer. Long-term results from a phase III study.

BACKGROUND: A randomised study in non-resectable rectal cancer showed that preoperative chemoradiotherapy (CRT) resulted in better local control and disease-specific survival, but not overall survival than radiotherapy alone. The present paper presents long-term (>4 years) health-related quality of life (HRQoL) and a comparison between the results and reference values from the Norwegian general population. MATERIAL AND METHODS: A total of 207 patients with primarily non-resectable rectal cancer were randomised to preoperative CRT (2Gyx25+5FU/leucovorin) or RT (2Gyx25) before surgery. HRQoL was assessed using EORTC QLQ-C30, completed at baseline and sent to all patients alive in Norway and Sweden (n=105) after a minimum of 4 years post treatment. A difference of ≥5 points on the 0-100 scales was considered clinically significant. RESULTS: Seventy-six (72%) patients answered at follow-up. No statistically significant differences between the CRT and RT groups appeared at follow-up, although clinically significant differences in social functioning, dyspnoea and diarrhoea were found. Over time, a clinically significant reduction in physical functioning was found in both groups. Moreover, reduced social functioning and less diarrhoea in the CRT group and better role functioning and more diarrhoea in the RT group were found. Comparisons between the study group and age and gender matched reference values indicate impaired social functioning and more diarrhoea among the patients. CONCLUSION: There were no statistically significant differences in HRQoL between the randomisation groups. In general, despite having impaired social functioning and more diarrhoea, patients reported HRQoL comparable with the reference population several years after treatment.

Delineation of gross tumor volume (GTV) for radiation treatment planning of locally advanced rectal cancer using information from MRI or FDG-PET/CT: a prospective study.

PURPOSE: Accurate delineation of target volumes is important to maximize radiation dose to the tumor and minimize it to nontumor tissue. Computed tomography (CT) and magnetic resonance imaging (MRI) are standard imaging modalities in rectal cancer. The aim was to explore whether functional imaging with F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET), combined with CT (FDG-PET/CT) gives additional information to standard pretreatment evaluation and changes the shape and size of the gross tumor volume (GTV). METHODS AND MATERIALS: From 2007 to 2009, 77 consecutive patients with locally advanced rectal cancer were prospectively screened for inclusion in the study at two university hospitals in Sweden, and 68 patients were eligible. Standard GTV was delineated using information from clinical examination, CT, and MRI (GTV-MRI). Thereafter, a GTV-PET was defined in the fused PET-CT, and the target volume delineations were compared for total volume, overlap, and mismatch. Pathologic uptake suspect of metastases was also registered. RESULTS: The median volume of GTV-MRI was larger than that of GTV-PET: 111 cm(3) vs. 87 cm(3) (p < 0.001). In many cases, the GTV-MRI contained the GTV defined on the PET/CT images as subvolumes, but when a GTV total was calculated after the addition of GTV-PET to GTV-MRI, the volume increased, with median 11% (range, 0.5-72%). New lesions were seen in 15% of the patients for whom PET/CT was used. CONCLUSIONS: FDG-PET/CT facilitates and adds important information to the standard delineation procedure of locally advanced rectal cancer, mostly resulting in a smaller GTV, but a larger total GTV using the union of GTV-MRI and GTV-PET. New lesions were sometimes seen, potentially changing the treatment strategy.

Late patient-reported toxicity after preoperative radiotherapy or chemoradiotherapy in nonresectable rectal cancer: results from a randomized Phase III study.

PURPOSE: Preoperative chemoradiotherapy (CRT) is superior to radiotherapy (RT) in locally advanced rectal cancer, but the survival gain is limited. Late toxicity is, therefore, important. The aim was to compare late bowel, urinary, and sexual functions after CRT or RT. METHODS AND MATERIALS: Patients (N = 207) with nonresectable rectal cancer were randomized to preoperative CRT or RT (2 Gy × 25 ± 5-fluorouracil/leucovorin). Extended surgery was often required. Self-reported late toxicity was scored according to the LENT SOMA criteria in a structured telephone interview and with questionnaires European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30), International Index of Erectile Function (IIEF), and sexual function-vaginal changes questionnaire (SVQ). RESULTS: Of the 105 patients alive in Norway and Sweden after 4 to 12 years of follow-up, 78 (74%) responded. More patients in the CRT group had received a stoma (73% vs. 52%, p = 0.09). Most patients without a stoma (7 of 12 in CRT group and 9 of 16 in RT group) had incontinence for liquid stools or gas. No stoma and good anal function were seen in 5 patients (11%) in the CRT group and in 11 (30%) in the RT group (p = 0.046). Of 44 patients in the CRT group, 12 (28%) had had bowel obstruction compared with 5 of 33 (15%) in the RT group (p = 0.27). One-quarter of the patients reported urinary incontinence. The majority of men had severe erectile dysfunction. Few women reported sexual activity during the previous month. However, the majority did not have concerns about their sex life. CONCLUSIONS: Fecal incontinence and erectile dysfunction are frequent after combined treatment for locally advanced rectal cancer. There was a clear tendency for the problems to be more common after CRT than after RT.

Randomized phase III study comparing preoperative radiotherapy with chemoradiotherapy in nonresectable rectal cancer.

PURPOSE: Preoperative chemoradiotherapy is considered standard treatment for locally advanced rectal cancer, although the scientific evidence for the chemotherapy addition is limited. This trial investigated whether chemotherapy as part of a multidisciplinary treatment approach would improve downstaging, survival, and relapse rate. PATIENTS AND METHODS: The randomized study included 207 patients with locally nonresectable T4 primary rectal carcinoma or local recurrence from rectal carcinoma in the period 1996 to 2003. The patients received either chemotherapy (fluorouracil/leucovorin) administered concurrently with radiotherapy (50 Gy) and adjuvant for 16 weeks after surgery (CRT group, n = 98) or radiotherapy alone (50 Gy; RT group, n = 109). RESULTS: The two groups were well balanced according to pretreatment characteristics. An R0 resection was performed in 82 patients (84%) in the CRT group and in 74 patients (68%) in the RT group (P = .009). Pathologic complete response was seen in 16% and 7%, respectively. After an R0 + R1 resection, local recurrence was found in 5% and 7%, and distant metastases in 26% and 39%, respectively. Local control (82% v 67% at 5 years; log-rank P = .03), time to treatment failure (63% v 44%; P = .003), cancer-specific survival (72% v 55%; P = .02), and overall survival (66% v 53%; P = .09) all favored the CRT group. Grade 3 or 4 toxicity, mainly GI, was seen in 28 (29%) of 98 and six (6%) of 109, respectively (P = .001). There was no difference in late toxicity. CONCLUSION: CRT improved local control, time to treatment failure, and cancer-specific survival compared with RT alone in patients with nonresectable rectal cancer. The treatments were well tolerated.

[Palliative chemotherapy and radiotherapy for metastatic colorectal cancer]. / Palliativ kjemoterapi og strålebehandling ved metastatisk kolorektal cancer.

BACKGROUND: There are 3 450 new cases of colorectal cancer in Norway annually. In half of the patients, metastatic disease will evolve with time. Palliative chemo- or radiotherapy can prolong disease- and symptom control when cure is not feasible. MATERIAL AND METHODS: This paper is based on publications retrieved from a PubMed search, the authors' knowledge of the field and on recent conference abstracts. RESULTS AND INTERPRETATION: Patients with metastatic colorectal cancer should initially be considered for surgery, and judged if secondary surgery is a possibility. Palliative chemotherapy is used to increase survival and maintain quality of life. 5-FU/calsiumfolinat combined with oxaliplatin or irinotecan is usually given as first line treatment for patients below 75 years--and most of them respond. Median survival is close to two years. Bevacizumab combined with an irinotecan regimen is an alternative first line treatment. Elderly patients are judged on an individual basis. Half of the patients will receive second line therapy with the alternative chemotherapy schedule. Cetuximab combined with irinotecan is a possible third line treatment. Palliative radiotherapy is most often used for inoperable rectal cancer, local recurrences, and bone or brain metastases.

Multicenter phase II study of Nordic fluorouracil and folinic acid bolus schedule combined with oxaliplatin as first-line treatment of metastatic colorectal cancer.

PURPOSE: This Nordic multicenter phase II study evaluated the efficacy and safety of oxaliplatin combined with the Nordic bolus schedule of fluorouracil (FU) and folinic acid (FA) as first-line treatment in metastatic colorectal cancer. PATIENTS AND METHODS: Eighty-five patients were treated with oxaliplatin 85 mg/m(2) as a 2-hour infusion on day 1, followed by a 3-minute bolus injection with FU 500 mg/m(2) and, 30 minutes later, by a bolus injection with FA 60 mg/m(2) every second week. The same doses of FU and FA were also given on day 2. RESULTS: Fifty-one of 82 assessable patients achieved a complete (n = 4) or partial (n = 47) response, leading to a response rate of 62% (95% CI, 52% to 72%). Nineteen patients showed stable disease, and 12 patients had progressive disease. Thirty-eight of the 51 responses were radiologically confirmed 8 weeks later (confirmed response rate, 46%; 95% CI, 36% to 58%). The estimated median time to progression was 7.0 months (95% CI, 6.3 to 7.7 months), and the median overall survival was 16.1 months (95% CI, 12.7 to 19.6 months) in the intent-to-treat population. Neutropenia was the main adverse event, with grade 3 to 4 toxicity in 58% of patients. Febrile neutropenia developed in seven patients. Nonhematologic toxicity consisted mainly of neuropathy (grade 3 in 11 patients and grade 2 in another 27 patients). CONCLUSION: Oxaliplatin combined with the bolus Nordic schedule of FU+FA (Nordic FLOX) is a well-tolerated, effective, and feasible bolus schedule as first-line treatment of metastatic colorectal cancer that yields comparable results compared with more complex schedules.

Total pelvic exenteration with preoperative irradiation for advanced primary and recurrent rectal cancer.

OBJECTIVE: To study the complication rate, local recurrence rate, and survival after total pelvic exenteration for primary advanced and recurrent rectal cancer. DESIGN: Prospective study. SETTING: Tertiary referral university hospital, Norway. SUBJECTS: 25 patients who were operated on for primary advanced and 22 for recurrent rectal cancer since 1991; 42 men and 5 women, mean age 64 years (range 44-78). All had preoperative irradiation of 46-50 Gy. MAIN OUTCOME MEASURES: Incidence of major complications, and actuarial 5-year survival and local recurrence rate. RESULTS: Twenty patients had RO resection in the primary group versus seven in the recurrent group. No R2 resections were done in the primary group compared with four in the recurrent group. Half the primary cases (n = 13) had abdominoperineal resections. Hartmann's procedures were common in both groups (n = 8 in each). Postoperative mortality at 30 days was 4% (n = 2) and in-hospital 13% (n = 6). 18 patients had major complications and 12 were reoperated on. Overall 5-year actuarial survival for 43 patients without distant metastases was 28%-those with primary tumours 36%, and those with recurrent tumours 18%-similar to the figures for RO and R1 resections. Actuarial local recurrence at 5 years for primary cancers was 18% compared with 68% for recurrent cancers, again nearly identical to the figures for R0/R1 operations (p = 0.008 and p = 0.03). CONCLUSION: Some patients with advanced rectal cancer either primary or recurrent may benefit from simultaneous en-bloc cystectomy. The higher postoperative morbidity and mortality indicate the need for well-defined indications for this procedure and the necessity for thorough preoperative staging.