The effect of postoperative pelvic irradiation after complete resection of metastatic rectal cancer

Efficacy of concurrent radiotherapy in patients with locally advanced rectal cancer and synchronous metastasis receiving systemic therapy

Background

Neoadjuvant chemoradiotherapy followed by total mesorectal excision is the standard treatment for patients with nonmetastatic locally advanced rectal cancer (LARC). However, for patients with LARC and synchronous metastasis, the optimal treatment strategy and sequence remain inconclusive. In the present study, we evaluated the efficacy and safety of concurrent radiotherapy in patients with de novo metastatic rectal cancer who received chemotherapy and targeted therapy.

Methods

We retrospectively reviewed the data of 63 patients with LARC and synchronous metastasis who received intensive therapy at the study hospital between April 2015 and November 2018. The included patients were divided into two groups: RT-CT, those who received systemic chemotherapy with targeted therapy and concurrent radiotherapy (for primary rectal cancer), and CT, those who received only systemic chemotherapy with targeted therapy.

Results

Treatment response was better in the RT-CT group than in the CT group. The rate of primary tumor resection (PTR) was higher in the RT-CT group than in the CT group (71.4% and 42.9%, respectively; P = .0286). The RT-CT group exhibited considerably longer local recurrence-free survival (P = .0453) and progression-free survival (PFS; from 13.3 to 22.5 months) than did the CT group (P = .0091); however, the groups did not differ in terms of overall survival (OS; P = .49). Adverse events were almost similar between the groups, except frequent diarrhea, the prevalence of which was higher in the RT-CT group than in the CT group (59.5% and 23.8%, respectively; P = .0075).

Conclusions

In the era of biologics, radiotherapy may increase the resectability of primary rectal tumors, reducing the risk of locoregional failure and prolonging PFS. Concurrent pelvic radiotherapy may not substantially improve OS, which is indicated by metastasis. Hence, the resection of the distant metastases may be essential for improving long-term OS. To further determine the efficacy of concurrent radiotherapy, additional prospective, randomized studies must combine preoperative pelvic radiotherapy with PTR and metastectomy to treat patients with stage IV LARC.

Neoadjuvant Pelvic Radiotherapy in the Management of Rectal Cancer with Synchronous Liver Metastases: Is It Worth It?

BACKGROUND

The use of neoadjuvant pelvic radiotherapy was a major advance in oncologic care for locally advanced rectal cancer in the twentieth century. The extrapolation of the care of locally advanced rectal cancer to the management of rectal cancer with treatable liver metastases is controversial. The aim of this review is to examine the available data on the role of pelvic radiotherapy and chemoradiation in the setting of treatable metastatic liver disease.

METHODS

A systematic search of MEDLINE was performed to report the landmark randomized controlled trials between 1993 and 2021.

RESULTS

Attaining liver clearance and total mesorectal excision with R0 margin remains the mainstay of cure. There is uncertainty regarding the sequencing of treatment. The literature lacks randomized clinical trials comparing the rectal first, liver first, interval strategy, and simultaneous surgical approaches. A multidisciplinary discussion regarding the utility of radiotherapy is emphasized to achieve the goals of treatment. Short-course radiotherapy has proved comparable disease-control outcomes to long-course chemoradiation with a significantly improved cost-performance. The implementation of short-course radiotherapy in the interval strategy and simultaneous surgical approach is promising. Neoadjuvant pelvic radiotherapy can be omitted in patients with metastatic rectal cancer if adequate margin clearance is achievable.

CONCLUSION

The use of radiotherapy in metastatic rectal cancer is popular but is based on limited data. Treatment should be tailored to the local extent of rectal cancer and priority of liver metastasis management. The optimal treatment strategy in patients with rectal cancer and synchronous liver metastatic disease needs to be studied in randomized trials.

Is There a Role for Perioperative Pelvic Radiotherapy in Surgically Resected Stage IV Rectal Cancer?: A Propensity Score-matched Analysis

OBJECTIVES

This study aimed to determine whether perioperative pelvic radiotherapy (RT) improves outcomes in stage IV rectal cancer patients treated with primary surgical resection and systemic chemotherapy and to identify predictive factors for selection of patients for these approaches.

MATERIALS AND METHODS

We searched the Surveillance, Epidemiology, and End Results (SEER) database for patients diagnosed between 2010 and 2015 with stage IV rectal cancer, but without brain or bone metastases. After applying the exclusion criteria, a total of 26,132 patients were included in the analysis; propensity score matching was used to balance their individual characteristics.

RESULTS

Overall, 3283 (12.6%) patients received perioperative RT; the 3-year overall survival (OS) rates were 43.6% in the surgery group and 50.5% in the surgery with RT group (P<0.001). The survival benefit of RT was maintained after propensity score matching and multivariate adjustment (hazard ratio: 0.70; 95% confidence interval: 0.66-0.81; P<0.001). Interaction testing of the prognostic variables showed a significant interaction between RT and the presence of lung metastasis (P<0.001): the benefit of RT was observed only in patients without lung metastases (3 y OS 52.1% vs. 44.1%, P<0.001), but it was observed regardless of liver metastases. In addition, we developed a web-based calculator (http://bit.do/mRC_surv) to provide individualized estimates of OS benefit based on the receipt of perioperative pelvic RT.

CONCLUSIONS

Perioperative pelvic RT significantly improved OS rates, especially in patients without lung metastases. We successfully developed a nomogram and web-based calculator that could predict survival benefit with the addition of RT for these patients.

Palliative beam radiotherapy offered real-world survival benefit to metastatic rectal cancer: A large US population-based and propensity score-matched study

Purpose: Radiotherapy (RT) has been reported to effectively palliate many symptoms of patients with metastatic rectal cancer (mRC). The objective of this study was to evaluate the survival benefit of RT in mRC. Methods: A retrospective population-based cohort study was performed using the Surveillance, Epidemiology, and End Results Program (SEER) database. Patient baseline demographic characteristics between the RT and no-RT groups were compared using Pearson chi-square tests. The outcome of interest was cause-specific survival (CSS). Propensity score (PS) matching and Cox proportional hazards regression analyses were performed to evaluate the prognostic power of variables on CSS. Results: A total of 8851 patients with mRC were identified in the SEER database. Multivariable Cox regression analysis showed that RT was a protective factor in mRC (hazard ratio [HR]= 0.702, 95% confidence interval [CI]=0.665-0.741, p<0.001). In subgroup analysis, multivariate Cox analysis demonstrated that patients of both surgery and no-surgery subgroups treated with RT had better CSS than those not treated with RT (HR=0.654, 95%CI=0.607-0.704, p<0.001 for the surgery group; HR=0.779, 95%CI=0.717-0.847, p<0.001 for the no-surgery group), PS matching resulted in 4170 mRC patients and RT group presented significantly improved survival benefit than no-RT group (22.0 vs. 13.5%, P <0.001). In surgery subgroup after PS matching, in especial, RT group showed more evidently improved survival benefit than no-RT group (30.3 vs. 18.0%, p <0.001). Conclusion: Using the SEER database, we definitely demonstrated that RT was associated with a significant survival advantage beyond the relief of a variety of pelvic symptoms in the setting of mRC. This study strongly supports the use of RT in selected patients with mRC, especially in patients who have undergone surgery. More studies need to be conducted to accurately define the role of RT in mRC.

Managing Synchronous Liver Metastases in Colorectal Cancer

The most common site of blood-borne metastases from colorectal cancers (CRC) is the liver. Resection of (liver) metastases is a part of standard treatment of metastatic colorectal cancer. Hepatic resection is the first-line treatment of liver metastases, with 5-year survival rates between 25 and 58%. The enhanced efficacy of systemic chemotherapeutic regimens has increased tumor response rates and improved the progression-free and overall survival of patients with these malignancies. In approximately 20% of patients with initially unresectable liver metastases, the metastases may become resectable after administration of neoadjuvant chemotherapy. Unresectable liver metastases can be managed with systemic therapy and/or a variety of liver-directed techniques such as radiofrequency ablation, hepatic artery infusion, or yttrium-90 radioembolization. Our examination of the literature led us to propose a new patient-oriented algorithm to guide clinicians' decisions on the best choice of upfront therapy for CRC and synchronous liver metastases. The need for multidisciplinary consensus has become especially important for metastatic CRC.

Elevated red blood cell distribution width contributes to poor prognosis in patients undergoing resection for nonmetastatic rectal cancer

Several studies have reported that elevated red blood cell distribution width (RDW) was associated with the poor prognosis of different kinds of cancers. The aim of this study was to investigate the prognostic role of RDW in patients undergoing resection for nonmetastatic rectal cancer.We retrospectively reviewed a database of 625 consecutive patients who underwent curative resection for nonmetastatic rectal cancer at our institution from January 2009 to December 2014. The cutoff value of RDW was calculated by receiver-operating characteristic curve.The results demonstrated that patients in high RDW-cv group had a lower overall survival (OS) (P = .018) and disease-free survival (P = .004). We also observed that patients in high RDW-sd group were associated with significantly lower OS (P = .033), whereas the disease-free survival (DFS) was not significantly different (P = .179).In multivariate analysis, we found elevated RDW-cv was associated poor DFS (hazard ratio [HR] = 1.56, P = .010) and RDW-sd can predict a worse OS (HR = 1.70, P = .009).We confirmed that elevated RDW can be an independently prognostic factor in patients undergoing resection for nonmetastatic rectal cancer. So more intervention or surveillance might be paid to the patients with nonmetastatic rectal cancer and elevated RDW values in the future.

The role of neoadjuvant radiotherapy for locally-advanced rectal cancer with resectable synchronous metastasis

BACKGROUND

Although neoadjuvant radiotherapy is typically administered for locally-advanced rectal cancer to reduce local recurrence (LR), its role for patients who present with synchronous resectable liver and/or lung metastasis is not well defined. The aim of this study was to evaluate the role of neoadjuvant radiotherapy for patients with stage IV rectal cancer undergoing curative-intent surgery.

METHODS

This study is a retrospective review of a prospectively maintained surgical registry of all consecutive adult patients who underwent curative-intent resection at Mayo Clinic in Rochester, MN, from January 1990 until December 2014 with a median follow-up time of 43 (IQR 16-67) months. Eligible patients had locally-advanced rectal cancer (T3, T4 and/or nodal involvement) with synchronous resectable liver and/or lung metastasis. Exclusion criteria were as follows: patients with primary tumor stage of T1N0 or T2N0, patients with metastasis to organs other than the liver or lung, patients who had palliative resection, patients who had non-surgical treatment of synchronous metastasis (e.g., radiofrequency ablation), patients who received postoperative radiotherapy, or absence of research authorization. Ninety three patients were included of which 47 received neoadjuvant radiotherapy and 46 did not. All patients received neoadjuvant chemotherapy +/- radiotherapy followed by curative-intent surgery with metastasectomy performed either simultaneously with resection of the primary tumor or as a planned staged resection. The primary outcomes of this study are LR, distant metastasis, overall and disease-specific survival (DSS).

RESULTS

LR was observed in 12 patients (26%) who did not receive radiotherapy, while no LR developed in those who received neoadjuvant radiotherapy, P<0.001. Univariate analysis showed that neither age, sex, ASA class, BMI, tumor location, procedure performed, or neoadjuvant chemotherapy were associated with subsequent LR. The 5-year overall survival (OS) rates were: 43.3% (95% CI: 30.1, 62.3) for no radiotherapy vs. 58.3% (95% CI: 43.4, 78.2) with radiotherapy.

CONCLUSIONS

Neoadjuvant radiotherapy should be considered in patients with locally-advanced stage IV rectal cancer. These data add to the evidence supporting neoadjuvant radiotherapy in the setting of resectable metastatic disease.

The impacts of surgery of the primary cancer and radiotherapy on the survival of patients with metastatic rectal cancer

The role of surgery of the primary cancer and radiation in metastatic colorectal cancer (mCRC) is still controversial currently, and evidence implied that colon cancer (CC) and rectal cancer (RC) should be treated with difference. Hence we focused on metastatic rectal cancer (mRC) solely to compare the cancer cause-specific survival (CSS) of patients receiving varied treatments of the primary cancer: no treatment, surgery only, radiation only, and surgery plus radiation, based on the records of the Surveillance, Epidemiology, and End Results (SEER) database. A total of 8669 patients were included. Results demonstrated that the 2-year CSS was 28.1% for no treatment group, 30.7% for only radiation group, 50.2% for only surgery group, and 66.5% for surgery plus radiation group, reaching statistical difference (P < 0.001). Furthermore, the CSSs of mRC patients in the surgery group were similar regardless of resection ranges (P = 0.44). Besides, we analyzed the prognostic factors for mRC and found carcinoembryonic antigen (CEA) level, metastasis (M) stage, Tumor (T) stage, tumor size, differentiate grade, age and marital status should be taken into consideration when estimating the prognosis. Particularly, patients with normal CEA level or M1a stage showed a significant survival advantage. Overall, present study suggested that surgery of the primary cancer and radiation might help to improve the survival of mRC patients, especially when both treatments were conducted. Our results may assist clinicians to make better treatment strategy for patients with mRC.

Adjuvant radiotherapy for the treatment of stage IV rectal cancer after curative resection: A propensity score-matched analysis and meta-analysis

The role of pelvic radiotherapy (RT) in stage IV rectal cancer with total mesorectal excision (TME) has not been defined. We evaluated the impact of RT on oncologic outcomes among patients with stage IV rectal cancer who underwent TME and performed a meta-analysis of published studies.The records of stage IV rectal cancer patients who underwent TME between August 2001 and December 2011 were reviewed. Patients who received pelvic RT (RT group) and those who did not (non-RT group) were matched using a propensity score. Oncologic outcomes were compared between the groups. A systematic literature search and meta-analysis was conducted.One hundred seventy-six patients were matched with propensity score matching, resulting in 39 patients in each group. The local recurrence-free survival (LRFS) of the RT group was significantly higher than that of the non-RT group (2-year LRFS: 100% vs 83.6%, respectively, P = 0.038). The overall survival, disease-free survival, and systemic recurrence were not significantly different between the groups. In the meta-analysis, the RT group had a reduced risk for loco-regional recurrence than the non-RT group (RR: 0.48, 95% confidence interval: 0.29-0.79).Pelvic RT might have benefits for loco-regional control in patients with stage IV rectal cancer who undergo TME.

Comparison of oncologic outcomes of metastatic rectal cancer patients with or without neoadjuvant chemoradiotherapy

PURPOSE

The aim of this study is to evaluate the effect of neoadjuvant chemoradiotherapy in stage IV rectal cancer.

METHODS

Primary rectal cancer patients with synchronous distant metastases between September 2001 and August 2011 were enrolled. Of 86 patients, 40 patients underwent neoadjuvant chemoradiotherapy (RTX group) and the remaining 46 patients underwent postoperative systemic chemotherapy without radiotherapy (NRTX group). Sharp mesorectal excision according to tumor location was performed. Oncologic outcomes were compared.

RESULTS

The lower tumor location was more common in RTX group than NRTX group (60.0 vs. 28.3%, P = 0.003). Clinical T and N status and American Society of Anesthesiologist (ASA) score were similar in both groups. The incidence of pathologic LN metastases in the NRTX group was 93.5% compared with 70.0% in RTX group (P = 0.007). Pattern of distant metastasis was similar between groups. However, metastatectomy was frequently performed in RTX group than NRTX group (57.5 vs. 30.4%, P = 0.020). There was no statistical difference in local recurrence rate between groups (10.0% in RTX vs. 15.2% in NRTX, P = 0.470). The median PFS was similar in both groups (12.00 months in RTX vs. 12.00 months in NRTX, P = 0.768). The median OS between groups was also not different (24.00 months in RTX vs. 27.00 months in NRT, P = 0.510).

CONCLUSIONS

Neoadjuvant chemoradiotherapy may not affect local control and overall survival in locally advanced rectal cancer with distant metastasis.

The Impact of Preoperative Radiation Therapy on Locoregional Recurrence in Patients with Stage IV Rectal Cancer Treated with Definitive Surgical Resection and Contemporary Chemotherapy

PURPOSE

Definitive resection of primary rectal cancers is frequently incorporated, with or without preoperative radiotherapy and perioperative chemotherapy, in the management of selected patients with metastatic rectal adenocarcinoma. This study reviews the impact of preoperative radiotherapy and perioperative chemotherapy on locoregional recurrence and overall survival in these patients.

METHODS AND MATERIALS

This retrospective study with an Institutional Review Board (IRB) waiver included 109 patients with metastatic rectal adenocarcinoma who underwent definitive primary resection between 1998 and 2011. In addition to resection, 64 patients were treated with preoperative radiotherapy and perioperative chemotherapy and 45 patients were treated with perioperative chemotherapy alone. Radiotherapy dose was typically 50.4 Gy. Baseline variables were compared using chi-square and unpaired t tests. Overall survival was calculated using Kaplan-Meier method. Univariate and multivariate analyses were performed using Cox proportional hazards regression.

RESULTS

There were no significant baseline differences between the two groups. There was no significant difference in locoregional recurrence (10.9 vs. 11.1%; p = 0.90) or overall survival (34.5 vs. 34.8 months; p = 0.89) for patients treated with preoperative radiotherapy compared to those treated with perioperative chemotherapy alone, respectively. Patients who underwent radiotherapy were less likely to have a positive margin (10.9 vs. 20.0%; p = 0.19), lymphovascular invasion (32.8 vs. 53.3%; p = 0.03), and pathologic stage N2 disease (25.0 vs. 42.2%; p = 0.02). Grade 2 postoperative complications were more common in the preoperative radiotherapy group (32.8 vs. 15.6%; p = 0.04). Multivariate analysis demonstrated that patients with poorly differentiated tumors (HR 2.19; p = 0.009) and those that did not undergo liver-directed therapy (HR 2.20; p = 0.005) had inferior survival.

CONCLUSIONS

Locoregional recurrence is modest in patients with metastatic rectal adenocarcinoma receiving definitive primary resection, irrespective of the use of radiotherapy. Preoperative radiotherapy may enhance pathologic downstaging at the expense of increased grade 2 postoperative complications. Its use should be reserved for patients at high risk for locoregional recurrence.

Rectal cancer: An evidence-based update for primary care providers

Rectal adenocarcinoma is an important cause of cancer-related deaths worldwide, and key anatomic differences between the rectum and the colon have significant implications for management of rectal cancer. Many advances have been made in the diagnosis and management of rectal cancer. These include clinical staging with imaging studies such as endorectal ultrasound and pelvic magnetic resonance imaging, operative approaches such as transanal endoscopic microsurgery and laparoscopic and robotic assisted proctectomy, as well as refined neoadjuvant and adjuvant therapies. For stage II and III rectal cancers, combined chemoradiotherapy offers the lowest rates of local and distant relapse, and is delivered neoadjuvantly to improve tolerability and optimize surgical outcomes, particularly when sphincter-sparing surgery is an endpoint. The goal in rectal cancer treatment is to optimize disease-free and overall survival while minimizing the risk of local recurrence and toxicity from both radiation and systemic therapy. Optimal patient outcomes depend on multidisciplinary involvement for tailored therapy. The successful management of rectal cancer requires a multidisciplinary approach, with the involvement of enterostomal nurses, gastroenterologists, medical and radiation oncologists, radiologists, pathologists and surgeons. The identification of patients who are candidates for combined modality treatment is particularly useful to optimize outcomes. This article provides an overview of the diagnosis, staging and multimodal therapy of patients with rectal cancer for primary care providers.

Is Chemoradiotherapy Beneficial for Stage IV Rectal Cancer?

PURPOSE

The aim of this study was to investigate the oncologic impact of preoperative or postoperative chemoradiotherapy on stage IV rectal cancer.

METHODS

A total of 140 consecutive patients with locally advanced mid-to-lower rectal cancer and resectable stage IV disease were prospectively enrolled. In total, 69 patients received chemoradiotherapy (26 preoperatively and 43 postoperatively); in contrast, 71 did not. Survival curves were constructed using the Kaplan-Meier method, and a multivariate analysis was performed to identify independent prognostic factors.

RESULTS

According to the multivariate analysis, radiation therapy was not an independent factor associated with either survival or recurrence. The overall survival curves revealed that patients who underwent radiotherapy tended to have a better survival compared with patients who did not undergo radiotherapy; however, this trend was not statistically significant (p = 0.057). The disease-free, local recurrence-free, and distant metastasis-free survival curves did not differ significantly between the two groups. The local recurrence-free survival rates for patients who underwent preoperative radiotherapy were significantly higher than those for patients who underwent postoperative radiotherapy (p = 0.042).

CONCLUSION

Preoperative radiotherapy, rather than postoperative radiotherapy, may improve local control of stage IV rectal cancer. However, chemoradiotherapy did not improve the survival of patients with stage IV rectal cancer in this study.

Patterns of care of radiation therapy in patients with stage IV rectal cancer: a Surveillance, Epidemiology, and End Results analysis of patients from 2004 to 2009

BACKGROUND

According to the 2013 National Comprehensive Cancer Network guidelines, pelvic radiation therapy (RT) is one of the preferred regimens for patients with metastatic rectal cancer (mRC). The objective of this study was to analyze patterns of care and outcomes data for the receipt of RT among patients with mRC using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Patients with stage IV rectal or rectosigmoid cancer were identified in the SEER database (2004-2009). Patients were stratified according to their primary disease site (rectum vs rectosigmoid), tumor (T) classification, and lymph node (N) classification. Treatment regimens (with or without surgical resection, with or without RT) were recorded. The Fisher exact test was used to compare RT rates based on stratified factors. Two and five-year survival rates were compared among treatment groups.

RESULTS

In total, 6873 patients with stage IV rectal cancer and 3417 patients with rectosigmoid cancer were identified. Overall, 20.5% of patients with rectal cancer underwent surgery alone, whereas 38.7% received RT with or without surgery. Within the rectosigmoid group, 51.4% of patients underwent surgery alone, and 15.1% received RT with or without surgery. The use of RT differed significantly between patients with in situ (Tis) through T2 tumors versus T3/T4 tumors (P < .001) and between those with N0 disease versus N1/N2 disease (P < .001). The 2-year and 5-year survival rates differed between treatment groups, with the highest survival rates observed among those who received combined surgery and RT.

CONCLUSIONS

The primary treatments for patients with mRC include RT with or without surgery. RT is used more commonly in patients with primary rectal (vs rectosigmoid) tumors, N0 disease, or Tis-T2 tumors. Treatment with combination surgery and RT is associated with prolonged survival.

Outcome of urinary bladder recurrence after partial cystectomy for en bloc urinary bladder adherent colorectal cancer resection

PURPOSE

Around 10 % of colorectal cancers are locally advanced at diagnosis. There are higher incidences for sigmoid and rectal cancer adhered to urinary bladder (UB) rather than other segments of colon cancer. Surgeons often performed partial cystectomy as possible for preservation of patient's life quality. This study investigates prognostic factors in patients who underwent bladder preservation en bloc resection for UB adherent colorectal cancer.

METHODS

From 2000 to 2011, 123 patients with clinically UB involvement colorectal cancer underwent primary colorectal cancer with urinary bladder resection. Seventeen patients were excluded because of the concurrent distant metastasis at diagnosis and another 22 patients were excluded because of total cystectomy with uretero-ileal urinary diversion. Finally, 84 patients with clinical stage IIIC (T4bN0M0, according to AJCC 7th edition) that underwent en bloc colorectal cancer resection with partial cystectomy were enrolled into this study for further analysis.

RESULTS

Preoperative colovesical fistula and positive CT result were significantly more in the urinary bladder invasion group (p = 0.043 and 0.010, respectively). Pathological UB invasion is an independent predictor of intravesical recurrence (p = 0.04; HR, 10.71; 95 % CI = 1.12∼102.94) and distant metastasis (p = 0.016; HR, 4.85; 95 % CI = 1.34 ∼ 17.53) in multivariate analysis.

CONCLUSIONS

For bladder preservation en bloc resection of urinary bladder adherent colorectal cancer, the pathological urinary bladder invasion is significantly associated with more urinary bladder recurrence and distant metastasis. This result helps surgeons make decisions at surgical planning and establish follow-up protocol.

The role of postoperative pelvic radiation in stage IV rectal cancer after resection of primary tumor

Purpose

To evaluate the effect of pelvic radiotherapy (RT) in patients with stage IV rectal cancer treated with resection of primary tumor with or without metastasectomy.

Materials and Methods

Medical records of 112 patients with stage IV rectal cancer treated with resection of primary tumor between 1990 and 2011 were retrospectively reviewed. Fifty-nine patients received synchronous or staged metastasectomy whereas fifty-three patients did not. Twenty-six patients received pelvic radiotherapy.

Results

Median overall survival (OS), locoregional recurrence-free survival (LRFS), and progression-free survival (PFS) of all patients was 27, 70, and 11 months, respectively. Pathologic T (pT), N (pN) classification and complete metastasectomy were statistically significant factors in OS (p = 0.040, 0.020, and 0.002, respectively). RT did not improve OS or LRFS. There were no significant factors in LRFS. pT and pN classification were also significant prognostic factors in PFS (p = 0.010 and p = 0.033, respectively). In the subgroup analysis, RT improved LRFS in patients with pT4 disease (p = 0.026). The locoregional failure rate of the RT group and the non-RT group were 23.1% and 33.7%, showing no difference in the failure pattern of both groups (p = 0.260).

Conclusion

Postoperative pelvic RT did not improve LRFS of all metastatic rectal cancer patients; however, it can be recommended to patients with pT4 disease. A complete resection of metastatic masses should be performed if possible.