Neoadjuvant chemotherapy without routine use of radiation therapy for patients with locally advanced rectal cancer: a pilot trial

Total neoadjuvant treatment, non-operative management and radiotherapy-free strategies: New approaches for the management of proficient mismatch repair/microsatellite stable locally advanced rectal cancer. A narrative review and evidence-based algorithm

In recent years, new therapeutic approaches have emerged in addition to classical neoadjuvant (chemo)radiotherapy for the treatment of locally advanced rectal cancer (LARC): total neoadjuvant treatment, non-operative management, and radiotherapy-free strategy. While the introduction of these approaches in a relatively short timeframe has quickly increased our therapeutic armamentarium, on the other hand it has complicated the decision-making process regarding the choice of the most appropriate treatment strategy for each patient with LARC. Therefore, a tool to interpret the evidence from clinical trials and to translate them into daily practice is highly demanded. In the present review, we address how these new developments are changing the multimodal treatment of LARC and offer an algorithm to integrate them into clinical practice.

Neoadjuvant Modified Infusional Fluorouracil, Leucovorin, and Oxaliplatin With or Without Radiation Versus Fluorouracil Plus Radiation for Locally Advanced Rectal Cancer: Updated Results of the FOWARC Study After a Median Follow-Up of 10 Years

We present 10-year results of the phase Ⅲ FOWARC trial, which evaluated the efficacy of modified infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) with or without radiation compared with fluorouracil with radiation in patients with locally advanced rectal cancer. A total of 495 patients age 18-75 years with stage Ⅱ-Ⅲ rectal cancer were randomly assigned to three treatment arms: fluorouracil plus radiotherapy, mFOLFOX6 plus radiotherapy, or mFOLFOX6 alone, followed by surgery and adjuvant chemotherapy. With a median follow-up of 10 years, the 10-year disease-free survival (DFS) rates were 52.5%, 62.6%, and 60.5%, respectively (P = .56). The 10-year locoregional recurrence (LR) rates were 10.8%, 8.0%, and 9.6% (P = .57), and the 10-year overall survival (OS) rates were 65.9%, 72.3%, and 73.4% (P = .90). Subgroup analysis identified ypTNM stage as a significant prognostic factor for DFS, LR, and OS (P < .0001, P < .006, P < .0001, respectively). Patients achieving pathologic complete response had 10-year DFS, LR, and OS rates of 84.3%, 3.0%, and 92.4%, respectively. No significant difference was observed in long-term survival outcome between mFOLFOX6 with and without radiation and fluorouracil plus radiation. These results demonstrate that neoadjuvant mFOLFOX6 chemotherapy can be considered as a therapeutic option in LARC.

Evidence-Based De-Escalation of Radiotherapy in Locally Advanced Rectal Cancer

Advancements in cancer care have significantly extended the life expectancy of rectal cancer patients and the impact of treatment-related toxicity on long-term quality of life has become a crucial factor in determining the most suitable type of neoadjuvant therapy, particularly for patients who are likely to undergo surgery. While radiotherapy has traditionally been regarded as the cornerstone for achieving improved local control in rectal cancer, it is accompanied by a range of associated complications, including bowel and bladder dysfunction, gonadal ablation, and Low Anterior Resection Syndrome. De-escalation of treatment is undoubtedly beneficial for many patients, and this approach should be tailored to consider their expectations while prioritizing patient care in decision-making. Although there is inadequate data to support the oncologic safety of a watch-and-wait approach without radiation or to omit radiation in patients with suspicious lateral pelvic lymph nodes, sufficient evidence exists to justify de-escalation by avoiding radiation before surgery in many other patients who respond well to chemotherapy.

Treatment Pattern and Outcome of Locally Advanced Rectal Cancer in Resource-Constrained Countries: Experience at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia

PURPOSE

Management of locally advanced rectal cancer (LARC) includes neoadjuvant chemoradiotherapy (NACRT) followed by total mesorectal excision. Recently, total neoadjuvant treatment (TNT) has gained attention. In developing countries, patients with rectal cancer often present at advanced stages. This study assesses treatment patterns and outcomes in LARC at a largest referral center in Ethiopia.

MATERIALS AND METHODS

A cross-sectional study was conducted on 100 patients with LARC treated at Tikur Anbessa Specialized Hospital from January 2020 to September 2022.

RESULTS

The median age at diagnosis was 45.5 years (range, 20-86), with 51% male. Of the patients, 81% had no previous oncologic treatment and 75.3% was discussed in a multidisciplinary tumor board. Up-front surgery was planned for 44.4% of patients, whereas 22.2% and 8.6% were assigned to TNT and NACRT, respectively. Among 81 treatment-naïve patients, 79 were triaged for surgery, but only 47 (59.5%) underwent surgery, achieving an 89.9% R0 resection rate. Of 36 up-front planned surgeries, 35 proceeded as planned, whereas only 12 of 43 (28%) planned after neoadjuvant treatment underwent surgery. Neoadjuvant chemotherapy (NACT) was given to 37% of patients, with 16.7% (5 of 30) undergoing subsequent surgery. Radiotherapy was given to 24.2% of participants, with 56.25% undergoing surgery. Short-course radiotherapy (SCRT) was given to two patients. Only 14.8% completed all planned treatments, with radiation waiting time (median, 10 months) being the main impediment.

CONCLUSION

Timely administration of neoadjuvant treatment is not possible in most resource-limited settings. Because of better treatment completion, up-front surgery looks a more viable option than NACT in these situations. Extended waiting time for radiotherapy can be mitigated by opting for alternatives like SCRT in selected patients.

Lateral node metastasis in low rectal cancer as a hallmark to predict recurrence patterns

BACKGROUND

Lateral node metastasis confers a poor prognosis in rectal cancer. Several multidisciplinary treatments have been proposed with favorable outcomes. However, appropriate neoadjuvant/adjuvant treatments or follow-up plans based on information about the probable recurrence site have not been specified. We aimed to clarify the distinctive features of recurrence patterns for lateral node-positive low rectal cancer according to the lateral and mesorectal lymph node status.

METHODS

We retrospectively analyzed 508 patients with stage III low rectal cancer who underwent lateral node dissection. We investigated the impact of lateral and mesorectal lymph node status on site-specific recurrence rates and patient survival.

RESULTS

Analyses for relapse-free survival revealed the prognostic impact of lateral node positivity in stage III low rectal cancer (p < 0.0001). Lateral node-positive patients exhibited higher risk of overall recurrence, local recurrence, and recurrence in extra-regional nodes than lateral node-negative patients (p < 0.0001, p = 0.001, and p < 0.0001, respectively). However, lateral node positivity was not statistically associated with a hematogenous recurrence rate. In lateral node-positive patients, both tumor-node-metastasis (TNM)-N status and number of lateral nodes involved were revealed as significant prognostic factors (p < 0.0001, both). In addition, the number of lateral nodes involved could be a discriminatory indicator of probabilities of local recurrence and recurrence in extra-regional nodes (p = 0.02, and p < 0.0001, respectively).

CONCLUSIONS

Lateral node-positive low rectal cancer exhibits higher local recurrence and extra-regional node recurrence rates that correlate with the number of lateral nodes involved.

Omission of Chemoradiation in Locally Advanced Rectal Adenocarcinoma: Evaluation of PROSPECT in a National Database

BACKGROUND AND OBJECTIVES

The PROSPECT trial showed noninferiority of neoadjuvant chemotherapy (NAC) with selective chemoradiation (CRT) versus CRT alone. However, trial results are often difficult to reproduce with real-world data. Pathologic outcomes and overall survival (OS) were evaluated by neoadjuvant strategy in locally advanced rectal adenocarcinoma patients in a national database.

METHODS

The 2012-2020 National Cancer Database was queried for clinical T2N1 and T3N0-1 rectal adenocarcinoma patients with definitive resection. Patients were categorized by neoadjuvant treatment with CRT alone, NAC alone, and NAC with CRT. Outcomes included R0 resection, pathologic complete response (PCR), and OS.

RESULTS

Of 18 892 patients, 16 126 (85.4%) received CRT, 1018 (5.4%) NAC, and 1748 (9.3%) NAC with CRT. Patients with NAC alone or NAC with CRT were more likely to have stage-III disease, private insurance, and academic facility treatment (all p < 0.001). NAC alone had lower adjusted odds of an R0 resection (OR 0.72; 95%CI 0.54-0.95) and PCR (OR 0.77; 95%CI 0.64-0.93). NAC with CRT demonstrated improved OS (HR 0.71; 95%CI 0.61-0.82), with no difference between NAC and CRT alone. Among patients who received adjuvant chemotherapy, no differences in OS were seen.

CONCLUSIONS

Patients who received NAC alone had worse pathologic outcomes. NAC had similar OS to CRT and NAC with CRT showed improved OS.

Blockade of CD73 potentiates radiotherapy antitumor immunity and abscopal effects via STING pathway

Radiotherapy (RT) is a crucial treatment for colorectal cancer (CRC) patients, but it often fails to induce systemic antitumor immunity. CD73, an immunomodulatory factor, is upregulated after RT and associated with poor prognosis in CRC patients. This study aims to elucidate the mechanisms driving RT-induced CD73 upregulation in CRC and investigate how combining RT with CD73 blockade stimulates immune responses and induces abscopal effects. Findings revealed that RT-induced CD73 upregulation is mediated by the ataxia telangiectasia and Rad3-related (ATR) pathway and correlated with RT tolerance, as demonstrated through flow cytometry, immunofluorescence, and Western Blotting. Using flow cytometry and multicolor immunofluorescence, experiments demonstrated that in CRC subcutaneous tumor models, combination therapy reduces the infiltration of myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), and regulatory T cells (Tregs) while increasing dendritic cells (DCs) and CD8 + T cells, resulting in superior antitumor responses. Additionally, results from flow cytometry, Western Blot, and RNA sequencing demonstrated that combination therapy enhances the antigen-presenting ability of DCs and activates tumor antigen-specific CD8 + T cells, improving their function and delaying their depletion. The activation of the cGAS-STING and IFN-I pathways is crucial for this effect. In summary, the integration of RT with CD73 blockade effectively reverses the immunosuppressive TME and invigorates CD8 + T cell-driven, specific antitumor immune responses. These insights shed fresh light on the mechanisms governing the synergistic modulation of immunity by RT and CD73 blockade in CRC, offering promising avenues for the advancement of therapeutic strategies against CRC.

mFOLFOX6 versus mFOLFOX6 + aflibercept as neoadjuvant treatment in MRI-defined T3-rectal cancer: a randomized phase-II-trial of the German Rectal Cancer Study Group (CAO/ARO/AIO 0214)

BACKGROUND

Neoadjuvant chemotherapy is an option for patients with locally advanced rectal cancer at low risk for local recurrence. This randomized phase II trial investigated whether the addition of aflibercept to modified FOLFOX6 (mFOLFOX6) could improve the rates of centrally confirmed pathological complete remissions (pCR) and (disease-free) survival in magnetic resonance imaging (MRI)-staged cT3 rectal cancer.

PATIENTS AND METHODS

Patients with rectal cancer fulfilling the following criteria were included: lower border of tumor >5 cm and <16 cm from anal verge; circumferential resection margin >2 mm and T3-tumor with a maximum infiltration of 10 mm, as determined by MRI. Patients were randomized 1 : 2 to six cycles mFOLFOX6 ± aflibercept. Surgery was scheduled 4 weeks after chemotherapy. Primary endpoint was the rate of centrally confirmed pCR. The study was designed to detect an improvement of pCR from 10% to 27% (power 80%, type I error 20%).

RESULTS

A total of 119 randomized patients started treatment (39 patients mFOLFOX6, arm A, and 80 mFOLFOX + aflibercept, arm B). The incidence of all grade adverse events was similar in both arms, however, adverse events grade ≥3 were more than twice as high in the experimental arm due to hypertension. Surgical complications were comparable. Aflibercept did not improve the pCR rate (arm A 26% versus arm B 19%, P = 0.47) and more patients in arm B had node positivity. With a median follow-up of 40.1 months, the 4-year disease-free survival was 83% in arm A and 85% in arm B (P = 0.82). Only two patients in arm A and one patient in arm B developed local recurrence.

CONCLUSIONS

In patients with locally advanced rectal cancer and MRI-defined low risk of local recurrence, neoadjuvant mFOLFOX6 + aflibercept was feasible and did not compromise surgery. Survival data were favorable in both arms, but pCR rates were not increased by the addition of aflibercept.

Is There any Benefit of Addition of Neo-Adjuvant Chemotherapy (FOLFOX4) to Standard Preoperative Treatment of Rectal Cancer? A Randomized Clinical Trial

BACKGROUND

Total neoadjuvant therapy (TNT) before surgical intervention represents a unique therapeutic approach for the management of locally advanced rectal cancer (LARC) and has witnessed a notable rise in utilization within recent years. However, the efficacy and safety of this treatment remain subjects of ongoing debate and investigation. This randomized controlled trial aimed to evaluate the potential impact of administering induction chemotherapy (IC) before the conventional neoadjuvant concomitant chemoradiotherapy (nCRT) in LARC patients.

MATERIALS & METHODS

patients with resectable stage II-III LARC were randomly allocated to receive either biweekly 6 cycles of FOLFOX4 regimen as IC followed by CRT and total mesorectal excision (TME) (experimental group) or nCRT followed by TME (control group). The primary endpoint was the rate of pathological complete response (pCR). The secondary endpoints encompassed the evaluation of treatment-related adverse events as well as the assessment of survival outcomes.

RESULTS

67 patients were enrolled in this study (32 in the experimental group and 35 in the control group). The median age of the patients was 45 years. Stage IIIB was observed in 46.3% of the patients. The patients who underwent induction chemotherapy demonstrated a notably higher rate of achieving pCR in comparison to the control group (28.1% vs 8.6%; P=0.001). There were no statistically significant differences observed in terms of their toxicity profile and survival outcomes.

CONCLUSIONS

Implementation of induction chemotherapy utilizing the FOLFOX4 regimen has demonstrated a notable enhancement in the rate of pathological complete response. However, this improvement does not appear to translate into significant advancements in overall survival outcomes.

Combined Resection Approaches: Decision Making for Synchronous Resection, Timing of Staged Intervention to Optimize Outcome

Advancement in systemic and regional radiation therapy, surgical technique, and anesthesia has provided a path for increased long-term survival and potential cure for more patients with stage IV rectal cancer in recent years. When patients have resectable disease, the sequence for surgical resection is classified in three strategies: classic, simultaneous, or combined, and reversed. The classic approach consists of rectal cancer resection followed by metastatic disease at a subsequent operation. Simultaneous resection addresses both rectal and metastatic disease in a single surgery. The reversed approach treats metastatic disease first, followed by the primary tumor in several months. Simultaneous resection is appropriate for selected patients to avoid delay of definitive surgery, and reduce number of surgeries, hospital stay, and cost to the health care system. It may also improve patients' psychological effect. Multidisciplinary discussions including colorectal and liver surgeons to review patients' baseline medical conditions, tumor biology and behavior, and disease burden and distribution is imperative to guide proper patient selection for simultaneous resection and perioperative treatments.

Do treated rectal tumors appear differently on MRI after chemotherapy versus chemoradiotherapy?

PURPOSE

Increasing studies have focused on neoadjuvant chemotherapy (NCT) in rectal cancer. However, few studies explored the differences in radiographic variation between patients treated with NCT and neoadjuvant chemoradiotherapy (NCRT).

METHODS

Stage II/III rectal cancer patients from March 2016 to December 2019 meeting the criteria treated with NCRT or NCT were included. MRI features, including tumor location, longitudinal length, DWI signal, MRI tumor regression grade (mrTRG), and radiomic texture features, before and after neoadjuvant treatments were reviewed.

RESULTS

116 patients with NCRT and 61 with NCT were analyzed. Among these patients, 46 patients in the NCRT group and 18 in the NCT group were responders with pathological TRG0-1. Within these responders, the mean tumor longitudinal length regression rate (TLRR) of the NCT group was 60.08 ± 11.17%, which was significantly higher than the 50.73 ± 15.28% of the NCRT group (p = 0.010). The proportion of high signal in the DWI image after NCT was higher than that of the NCRT group (88.89% vs 50.00%, p = 0.004). NCT responders had significantly higher median change rates than those of NCRT responders in 11 radiomic features, especially those shape features.

CONCLUSION

MRI images change differently between responders treated with NCRT and those with NCT in rectal cancer. The tumor volumetry and some radiomic features change more obviously in NCT responders, and the tumor signal changes more obviously in NCRT responders. During the evaluation of the response of the tumor to the neoadjuvant treatments, images of patients should be treated differently.

Immune checkpoint status and oncogenic mutation profiling of rectal cancer after neoadjuvant chemotherapy (KSCC1301-A2)

Aim

Immune checkpoint inhibitors (ICIs) are less effective in mismatch repair (MMR)-proficient (pMMR) colorectal cancers (CRCs) than in MMR-deficient CRCs. Here, we investigated changes in the tumor microenvironment after neoadjuvant chemotherapy (NAC) without radiotherapy in locally advanced rectal cancer (LARC) and the potential of ICIs as therapeutic agents for pMMR CRCs.

Methods

This was an ad hoc analysis of a KSCC1301 randomized phase II trial in which patients with untreated resectable LARC were randomly assigned to receive S-1 and oxaliplatin or folinic acid, 5-fluorouracil, and oxaliplatin as NAC. Forty-nine patients were studied in this ad hoc analysis. As a reference cohort, we assessed 25 rectal cancer patients who underwent surgery without NAC outside the randomized trial. Immune checkpoint molecules (ICMs; PD-1, PD-L1, CTLA-4, LAG3), tumor-infiltrating lymphocytes (TILs; CD8, FOXP3), and other related proteins were evaluated by immunohistochemistry. Next-generation sequencing (NGS) using Oncomine™ Comprehensive Assay version 3 was conducted in 23 patients.

Results

The expression levels of PD-1, CTLA-4, and LAG3 in the NAC group were significantly higher than in reference patients (p < 0.001). Additionally, the infiltration of CD8+ and FOXP3+ T cells, and the CD8/FOXP3 ratio were significantly higher in the NAC group than in reference patients (p < 0.0001). NGS analysis revealed no specific gene alteration related to TILs or ICMs.

Conclusion

We demonstrated changes in the tumor immune microenvironment after NAC in pMMR rectal cancer. NAC was associated with increased expression of ICMs and TILs. Rectal cancer could be susceptible to combined immunotherapy with chemotherapy.

Modified FOLFOX6 with Cetuximab versus with Radiotherapy in Neoadjuvant Treatment of Locally Advanced Rectal Cancer: A Single-Center, Prospective, Randomized Controlled Trial

In this trial, the feasibility and efficacy of neoadjuvant chemotherapy with targeted agents in the treatment of patients with locally advanced rectal cancer were evaluated. In this single-center, prospective, randomized controlled trial, we randomly assigned (1 : 1) patients with locally advanced rectal cancer with wild-type RAS/BRAF gene to two groups: 5 cycles of modified leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin combination regimen (modified FOLFOX6, mFOLFOX6) concurrent with 25 times radiotherapy or 5 cycles of mFOLFOX6 plus cetuximab, all with subsequent total mesorectal excision (TME) resection and adjuvant chemotherapy. We performed a random assignment by a computer-generated random number sequence. The primary end point was the R0 resection rate. The secondary end points were rates of pathologic complete response, downstaging, adverse events, postoperative complications, preventive enterostomy and low anterior resection syndrome. From January 6, 2020 to October 28, 2022, 80 patients were assigned and evaluated. In the mFOLFOX6-RT and mFOLFOX6-Cet groups, the rate of R0 resection was 96.7 and 96.9% (p = 1.000); the rate of pathological complete response (pCR) was 23.3 and 21.9% (p = 0.891); and the rate of downstaging (ypStage 0 to 1) was 53.3 and 53.1% (p = 1.000), respectively. No statistical differences between the two groups were observed in the incidence of adverse events and postoperative complications. Additionally, lower rates of preventive enterostomy and low anterior resection syndrome were shown in the mFOLFOX6-Cet group compared to the mFOLFOX6-RT group. The neoadjuvant treatment strategy of mFOLFOX6 with cetuximab is feasible and promising for patients with locally advanced rectal cancer, even superior to mFOLFOX6 with radiotherapy.

Neoadjuvant chemotherapy (CAPOX) alone for low- and intermediate-risk stage II/III rectal cancer: Long-term follow-up of a prospective single-arm study

BACKGROUND

Stratified treatment has been recommended for rectal cancer. Our previous multicenter randomized trial showed that low-/intermediate-risk rectal cancer patients did not benefit much from neoadjuvant chemoradiotherapy. In our phase II study, we found that stage II/III rectal cancer patients with low-/intermediate risks can be managed by neoadjuvant chemotherapy alone and achieve a good response. The current study aimed to report the long-term survival outcomes in the expanded phase II trial.

METHOD

Consecutive patients diagnosed with mid-low stage II/III rectal cancer with low/intermediate risk factors were included. Four cycles of neoadjuvant chemotherapy (CAPOX) were given, and MRI was used for tumour response detection. The primary endpoint was disease-free survival. The secondary endpoints were tumour response to NCT, tumour-related death, and overall survival.

RESULTS

This study enrolled 121 eligible patients. The good tumour response rate based on MRI was 82.6 %, with a pathological complete response (pCR) rate of 18.3 %. The disease-free survival rate was 82.6 %, and the overall survival rate was 96.7 % after a median follow-up time of 40 months. Two patients (1.7 %) suffered local recurrence, and 15 patients (12.4 %) suffered distant metastasis. The median disease-free survival and overall survival were 37 (9-60) and 40 (16-60) months, respectively. Tumour longitudinal length reduction and tumour regression grade on MRI were identified as predictors for poor tumour response to neoadjuvant chemotherapy.

CONCLUSION

In stage II/III rectal cancer patients with low-/intermediate risks, neoadjuvant chemotherapy alone may result in an acceptable tumour response and disease-free survival. Tumour response might be predicted early.

Frizzled-3 suppression overcomes multidrug chemoresistance by Wnt/β-catenin signaling pathway inhibition in hepatocellular carcinoma cells

Multidrug resistance (MDR) is a major obstacle to the efficacy of hepatocellular carcinoma (HCC) chemotherapy. Previous studies have identified that low FZD3 predicted decreased survival after intraperitoneal versus intravenous-only chemotherapy in ovarian cancer. This study aimed to identify a potential target in HCC chemotherapy. The FZD3 expression variant in HCC cell lines was detected by RT-qPCR and western blotting. The FZD3 expression in the early recurrent HCC group (RE group) and the non-early recurrent HCC group (non-RE group) was measured by RT-qPCR. Then, the 50% inhibitory concentrations (IC50) in HCC cell lines were studied by MTT assay. TOP/FOP FLASH luciferase assay was performed to measure TCF-binding activities. We found that FZD3 was upregulated in three HCC cell lines, and the FZD3 expression was significantly higher in the RE group than in the non-RE group (P = 0.0344). A positive correlation between FZD3 and MDR1 was observed in HCC tissues (R2 = 0.6368, P = 0.0001). Then, we found that FZD3 knockdown significantly altered Huh-7 cell chemotherapeutic sensitivity to cisplatin [50.43 µM in the FZD3 siRNA (siFZD3) group vs 98.59 µM in the siRNA negative control (siNC) group; P = 0.007] or doxorubicin (7.43 µM in the siFZD3 group vs 14.93 µM in the siNC group; P = 0.017). TOP/FOP FLASH luciferase assay showed FZD3 could inhibit Wnt/β-catenin signaling in HCC cells. Moreover, FZD3 expression knockdown in SNU-449 and Huh-7 cells markedly reduced β-catenin and phosho-β-catenin (S37) protein expression, and Cyclin D1, c-myc and MDR1 were significantly decreased. This is the first study to describe the significantly increased FZD3 expression in patients with early recurrent HCC. FZD3 knockdown led to increased sensitivity to chemotherapy by Wnt/β-catenin signaling inhibition in HCC cell lines. Our study suggests FZD3 as a potential target for reversing chemoresistance in HCC.

Treatment response prediction of neoadjuvant chemotherapy for rectal cancer by deep learning of colonoscopy images

In current clinical practice, several treatment methods, including neoadjuvant therapy, are being developed to improve overall survival or local recurrence rates for locally advanced rectal cancer. The response to neoadjuvant therapy is usually evaluated using imaging data collected before and after preoperative treatment or postsurgical pathological diagnosis. However, there is a need to accurately predict the response to preoperative treatment before treatment is administered. The present study used a deep learning network to examine colonoscopy images and construct a model to predict the response of rectal cancer to neoadjuvant chemotherapy. A total of 53 patients who underwent preoperative chemotherapy followed by radical resection for advanced rectal cancer at the Osaka University Hospital between January 2011 and August 2019 were retrospectively analyzed. A convolutional neural network model was constructed using 403 images from 43 patients as the learning set. The diagnostic accuracy of the deep learning model was evaluated using 84 images from 10 patients as the validation set. The model demonstrated a sensitivity, specificity, accuracy, positive predictive value and area under the curve of 77.6% (38/49), 62.9% (22/33), 71.4% (60/84), 74.5% (38/51) and 0.713, respectively, in predicting a poor response to neoadjuvant therapy. Overall, deep learning of colonoscopy images may contribute to an accurate prediction of the response of rectal cancer to neoadjuvant chemotherapy.

GRECCAR 14 - a multicentric, randomized, phase II-III study evaluating the tailored management of locally advanced rectal carcinoma after a favourable response to induction chemotherapy: Study protocol

AIM

Total neoadjuvant treatment (TNT) is becoming standard in patients with locally advanced rectal carcinoma (LARC). Preoperative chemoradiotherapy (CRT) has proven side effects on bowel and genitourinary function. An early tumoral response to induction chemotherapy demonstrates its high prognostic value. Tailored management could be used as an alternative to systematic CRT. The GRECCAR 14 trial will attempt to personalize treatment strategy according to the patient's early tumour response to intensive chemotherapy with the aim of achieving the best toxicity-efficiency ratio.

METHOD

GRECCAR 14 is a multicentric, randomized, two-arm, phase II-III noninferiority trial. Patients with mid or low LARC with a predictive circumferential resection margin ≤2 mm or T3c-d stage with extramural venous invasion will be included. Evaluation of the tumoral response will be performed after six courses of high-dose FOLFIRINOX chemotherapy. Good responders (GRs) will be defined by a 60% decrease in tumoral volume on magnetic resonance imaging. Patients will be randomized to CRT before surgery. The primary endpoints will be R0 resection for phase II and the 3-year disease-free survival (DFS) for phase III.

RESULTS

Tailored management of LARC is becoming an exciting challenge for the modality of neoadjuvant treatment and for the type of surgery or its omission. Neoadjuvant FOLFIRINOX has established efficacy, with a significant increase in the 3-year DFS. Better control of systemic disease must be accompanied by the same locoregional control, with the lowest morbidity. Our previous GRECCAR 4 trial demonstrated the high value of the early tumoral response after induction chemotherapy and the long-term safety of tailored management for GRs.

CONCLUSION

If GRECCAR 14 demonstrates the ability to tailor TNT for LARC, this could lead to changes in clinical practice.

Is Nonoperative Management of Rectal Cancer Feasible?

During the past decade, the treatment of locally advanced rectal cancer (LARC) has become more complex. Total neoadjuvant treatment (TNT) has increased the rates of both clinical and pathologic complete response, resulting in improved long-term oncological outcomes. The feasibility to implement nonoperative management (NOM) depends on solving current challenges such as how to correctly identify the best candidates for a NOM without compromising oncologic safety. NOM should be part of the treatment discussion of LARC, considering increasing rates of clinical complete response, potential quality of life gains, avoidance of surgical morbidity, and patient preferences.

Novel Chemotherapy Modalities for Different Cancers

Even though many of the approved drugs still have high systemic toxicity due to a lack of tumor selectivity and present pharmacokinetic drawbacks, like low water solubility, that negatively influence the drug circulation time and bioavailability, the anti-cancer study has produced commendable results in recent years. The stability tests carried out under stressful exposure to high temperatures, hydrolytic media, or light sources during their development or under moderate settings have shown the vulnerability of anti-cancer medications to various factors. Because of this, the development of degradation products is considered hospital waste in pharmaceutical formulations and the environment. Until now, various formulations have been created for attaining tissue-specific therapeutic targeting, lowering harmful side effects, and enhancing drug stability. To boost the specificity, efficiency, and durability of active molecules that are targeted in cancer therapy the invention of prodrugs is the potential approach. The latest study illustrates that the solubility, pharmacokinetics, cellular uptake, and stability of chemotherapy drugs can be improved through the incorporation of them into vesicular systems, such as polymeric micelles or cyclodextrins, or via nanocarriers containing chemotherapeutics linked to monoclonal antibodies. In this review article, we provide an overview of the most recent advances in the field of designing very stable prodrugs or nanosystems that are powerful anti-cancer medications and their actions on the body.

Preoperative Treatment of Locally Advanced Rectal Cancer

BACKGROUND

Pelvic radiation plus sensitizing chemotherapy with a fluoropyrimidine (chemoradiotherapy) before surgery is standard care for locally advanced rectal cancer in North America. Whether neoadjuvant chemotherapy with fluorouracil, leucovorin, and oxaliplatin (FOLFOX) can be used in lieu of chemoradiotherapy is uncertain.

METHODS

We conducted a multicenter, unblinded, noninferiority, randomized trial of neoadjuvant FOLFOX (with chemoradiotherapy given only if the primary tumor decreased in size by <20% or if FOLFOX was discontinued because of side effects) as compared with chemoradiotherapy. Adults with rectal cancer that had been clinically staged as T2 node-positive, T3 node-negative, or T3 node-positive who were candidates for sphincter-sparing surgery were eligible to participate. The primary end point was disease-free survival. Noninferiority would be claimed if the upper limit of the two-sided 90.2% confidence interval of the hazard ratio for disease recurrence or death did not exceed 1.29. Secondary end points included overall survival, local recurrence (in a time-to-event analysis), complete pathological resection, complete response, and toxic effects.

RESULTS

From June 2012 through December 2018, a total of 1194 patients underwent randomization and 1128 started treatment; among those who started treatment, 585 were in the FOLFOX group and 543 in the chemoradiotherapy group. At a median follow-up of 58 months, FOLFOX was noninferior to chemoradiotherapy for disease-free survival (hazard ratio for disease recurrence or death, 0.92; 90.2% confidence interval [CI], 0.74 to 1.14; P = 0.005 for noninferiority). Five-year disease-free survival was 80.8% (95% CI, 77.9 to 83.7) in the FOLFOX group and 78.6% (95% CI, 75.4 to 81.8) in the chemoradiotherapy group. The groups were similar with respect to overall survival (hazard ratio for death, 1.04; 95% CI, 0.74 to 1.44) and local recurrence (hazard ratio, 1.18; 95% CI, 0.44 to 3.16). In the FOLFOX group, 53 patients (9.1%) received preoperative chemoradiotherapy and 8 (1.4%) received postoperative chemoradiotherapy.

CONCLUSIONS

In patients with locally advanced rectal cancer who were eligible for sphincter-sparing surgery, preoperative FOLFOX was noninferior to preoperative chemoradiotherapy with respect to disease-free survival. (Funded by the National Cancer Institute; PROSPECT ClinicalTrials.gov number, NCT01515787.).

Comparison of the pathological response to 2 or 4 cycles of neoadjuvant CAPOX in II/III rectal cancer patients with low/intermediate risks: study protocol for a prospective, non-inferior, randomized control trial (COPEC trial)

BACKGROUND

For patients with low- and intermediate-risk stage II/III rectal cancer, current studies have reached a consensus that preoperative radiotherapy may be dispensed with, and neoadjuvant chemotherapy (NCT) alone might achieve an accepted local control. Our previous phase II study has evidenced that the morphological response of NCT could be better judged at a relatively early stage. Low- and intermediate-risk stage II/III rectal cancer patients could achieve a high rate of tumor shrinkage and downgrade after only 4 cycles of NCT and obvious tumor morphological changes could be observed after 2 cycles of NCT. However, there is still a lack of more detailed stratification and evidence for pathological criteria. The aim of the present study (comparison of the pathological response to 2 or 4 cycles of neoadjuvant CAPOX in II/III rectal cancer patients with low/intermediate risks, COPEC trial) is to determine the pathological tumor regression grade (pTRG) rate of 2 or 4 cycles of NCT in low- and intermediate-risk stage II/III rectal cancer and verify the feasibility of early identification of chemotherapy-insensitive population.

METHODS/DESIGN

This is a multicenter, prospective, non-inferior, randomized controlled trial (RCT) initiated by West China Hospital of Sichuan University and designed to be conducted in fourteen hospitals around China. Eligible patients will be centrally randomized into 2 or 4 cycles of CAPOX in a 1:1 ratio using the central automated randomization system offered by the O-trial online system ( https://plus.o-trial.com/ ) and accept total mesorectal excision after 2 or 4 cycles of CAPOX (oxaliplatin 130 mg/m², once daily on day 1, every 21 days and capecitabine 1000 mg/m², twice daily on days 1 to 14, every 21 days). The primary endpoint is the proportion of patients with pathological no-tumor regression (pTRG 3), which is determined postoperatively by each sub-center and verified by the primary center.

DISCUSSION

COPEC trial is designed to verify that the preoperative CAPOX chemotherapy for low- and intermediate-risk stage II/III rectal cancer could achieve a good response judgment after 2 cycles and obtain the tumor pathological response rate after 2 cycles of CAPOX. We hope the COPEC trial could help in establishing a consensus standard of low- and intermediate-risk rectal cancer and the early identification of stage II/III rectal patients with low- and intermediate-risk who are poorly responding to NCT.

TRIAL REGISTRATION

Clinicaltrial.gov NCT04922853. Registered on June 4, 2021.

Use of lymph node ratio to guide clinical decision-making concerning adjuvant radiotherapy in pT1-2N1 rectal cancer

PURPOSE

Lymph node metastases are uncommon in pT1-2 rectal cancer. pT1-2N1 are often characterized with low tumor burden and intermediate prognosis. Therefore, adjuvant radiotherapy (ART) is controversial in these patients. This study aimed to investigate the value of ART in pT1-2 rectal cancer and evaluate the guiding role of lymph node ratio (LNR) for utilization of ART.

METHODS

pT1-2N1 rectal cancer patients who received surgery without neoadjuvant radiotherapy between 2000 and 2018 with at least 12 lymph node harvest were extracted from the Surveillance, Epidemiology and End Results (SEER) database. We used time-dependent receiver operating characteristic (ROC) analysis to determine the optimal cutoff of LNR. Kaplan-Meier methods and Cox proportional hazards regression models were performed to determine the prognostic value of ART in pT1-2N1 rectal cancer patients and subgroups stratified by LNR.

RESULTS

A total of 674 and 1321 patients with pT1N1 and pT2N1 rectal cancer were eligible for analysis. There was no statistical cancer-specific survival (CSS) difference in pT1N1 rectal cancer patients between receiving and not receiving ART (P = 0.464). The 5-year CSS was 89.6% and 83.2% in pT2N1 rectal cancer patients between receiving and not receiving ART, respectively (P = 0.003). A total of 7.0% was identified as the optimal cutoff value of LNR. Survival improvement offered by ART was only found in LNR ≥ 7.0% subgroup (5-year CSS: 89.5% versus 79.6%, P = 0.003) instead of LNR < 7.0% subgroup (5-year CSS: 89.9% versus 86.3%, P = 0.208).

CONCLUSION

ART show substantial survival benefit in pT2N1 rectal cancer patients with LNR ≥ 7.0%, warranting the conventional adoption of ART in this subgroup.

Neoadjuvant Chemotherapy With CAPOX Versus Chemoradiation for Locally Advanced Rectal Cancer With Uninvolved Mesorectal Fascia (CONVERT): Initial Results of a Phase III Trial

OBJECTIVE

To compare neoadjuvant chemotherapy (nCT) with CAPOX alone versus neoadjuvant chemoradiotherapy (nCRT) with capecitabine in locally advanced rectal cancer (LARC) with uninvolved mesorectal fascia (MRF).

BACKGROUND DATA

nCRT is associated with higher surgical complications, worse long-term functional outcomes, and questionable survival benefits. Comparatively, nCT alone seems a promising alternative treatment in lower-risk LARC patients with uninvolved MRF.

METHODS

Patients between June 2014 and October 2020 with LARC within 12 cm from the anal verge and uninvolved MRF were randomly assigned to nCT group with 4 cycles of CAPOX (Oxaliplatin 130 mg/m2 IV day 1 and Capecitabine 1000 mg/m2 twice daily for 14 d. Repeat every 3 wk) or nCRT group with Capecitabine 825 mg/m² twice daily administered orally and concurrently with radiation therapy (50 Gy/25 fractions) for 5 days per week. The primary end point is local-regional recurrence-free survival. Here we reported the results of secondary end points: histopathologic response, surgical events, and toxicity.

RESULTS

Of the 663 initially enrolled patients, 589 received the allocated treatment (nCT, n=300; nCRT, n=289). Pathologic complete response rate was 11.0% (95% CI, 7.8-15.3%) in the nCT arm and 13.8% (95% CI, 10.1-18.5%) in the nCRT arm ( P =0.33). The downstaging (ypStage 0 to 1) rate was 40.8% (95% CI, 35.1-46.7%) in the nCT arm and 45.6% (95% CI, 39.7-51.7%) in the nCRT arm ( P =0.27). nCT was associated with lower perioperative distant metastases rate (0.7% vs. 3.1%, P =0.03) and preventive ileostomy rate (52.2% vs. 63.6%, P =0.008) compared with nCRT. Four patients in the nCT arm received salvage nCRT because of local disease progression after nCT. Two patients in the nCT arm and 5 in the nCRT arm achieved complete clinical response and were treated with a nonsurgical approach. Similar results were observed in subgroup analysis.

CONCLUSIONS

nCT achieved similar pCR and downstaging rates with lower incidence of perioperative distant metastasis and preventive ileostomy compared with nCRT. CAPOX could be an effective alternative to neoadjuvant therapy in LARC with uninvolved MRF. Long-term follow-up is needed to confirm these results.

Long-term results of a phase 2 study of neoadjuvant chemotherapy with molecularly targeted agents for locally advanced rectal cancer

BACKGROUND

We previously reported the feasibility and efficacy of neoadjuvant chemotherapy without radiotherapy for locally advanced rectal cancer. Here, we report the results of a long-term follow-up study.

METHODS

This was a multi-institutional, prospective phase 2 study of patients with locally advanced rectal cancer. Patients received neoadjuvant chemotherapy with molecularly targeted agents before undergoing total mesorectal excision. Six cycles of modified FOLFOX (mFOLFOX6) with bevacizumab were administered to KRAS-mutant patients, and mFOLFOX6 with cetuximab was administered to KRAS-wild-type patients. Here, we report the secondary end points of overall survival, relapse-free survival, and local recurrence rate.

RESULTS

Sixty patients were enrolled in this study. R0 resection was achieved in 98.3% (59/60) patients, and pathological complete response was achieved in 16.7% (10/60) patients. After a median follow-up of 5.4 years, the 5 year overall survival was 81.6%, the 5 year relapse-free survival was 71.7%, and the 5 year local recurrence rate was 12.6%. None of the patients who achieved pathological complete response developed recurrence within 5 years.

CONCLUSIONS

The use of molecularly targeted agents in the neoadjuvant setting for locally advanced rectal cancer has an acceptable prognosis.

A phase II study of neoadjuvant capecitabine, oxaliplatin, and irinotecan (XELOXIRI) in patients with locally advanced rectal cancer

PURPOSE

Addition of perioperative multi-agent chemotherapy to the treatment strategy for locally advanced rectal cancer (LARC) may be a promising option. We conducted a phase II study to evaluate the safety and efficacy of capecitabine combined with oxaliplatin and irinotecan (XELOXIRI) as triplet neoadjuvant chemotherapy in patients with LARC.

METHODS

Patients received neoadjuvant irinotecan and oxaliplatin and capecitabine and then underwent total mesorectal excision. The primary study endpoint was the pathological complete response (pCR) rate.

RESULTS

Between June 2013 and December 2016, 55 patients were enrolled in the study. Forty-two (77.8%) of 54 completed the study protocol. The pCR rate was 7.7% (95% CI 3.0% to 18.2%). The 3-year local recurrence rate was 3.9%, the 3-year disease-free survival (DFS) rate was 77.3, and the 3-year overall survival rate was 96.0%.

CONCLUSION

XELOXIRI neoadjuvant chemotherapy appears to be feasible and efficacious for patients with LARC. Although neoadjuvant XELOXIRI alone did not yield our expected pCR rate, the local recurrence rate, 3-year DFS, and measures of safety met current standards.

Changing patterns of neoadjuvant therapy for locally advanced rectal cancer: A narrative review

Standard treatment for patients with locally advanced rectal cancer has been the multidisciplinary approach of neoadjuvant chemoradiotherapy, followed by total mesorectal excision (TME) and postoperative adjuvant chemotherapy. This reduces the local recurrence rate, but the challenge of distant metastasis still persists. The improvement in treatment approach has always been the focus of clinical research and studies have been conducted worldwide in recent years. On one hand, evidence suggests that increasing the intensity of treatment can result in better tumor regression, for example by adding a second drug to the neoadjuvant chemoradiotherapy, or extending the interval between neoadjuvant therapy and surgery, or incorporating chemotherapy and chemoradiotherapy in the neoadjuvant setting. On the other hand, neoadjuvant immunotherapy and selective omission of neoadjuvant radiotherapy may improve the quality of life of patients. In this article, we review the key clinical research progresses in neoadjuvant therapy for locally advanced rectal cancer, hoping to provide some valuable views on the individualized treatment for rectal cancer.

Efficacy of neoadjuvant CapeOX/mFOLFOX6 without radiation for patients with baseline resectable mid-low locally advanced rectal cancer

OBJECTIVES

Chemotherapy without radiation therapy for locally advanced rectal cancer (LARC) has attracted increasing attention, but the optimal schema remains controversial. In this study, we aimed to assess the efficacy and toxicity of neoadjuvant chemotherapy (nCT) of two regimens for patients with mid-low baseline resectable LARC.

METHODS

A retrospective study was performed in 131 patients with baseline resectable LARC in a single center between April 2016 and August 2020. All patients received four cycles of neoadjuvant CapeOX or mFOLFOX6 before surgery. Clinical characteristics, pathological response, and survival status were then assessed.

RESULTS

After a 1:1 propensity score matching, 96 patients were enrolled, including 48 receiving CapeOX and 48 receiving mFOLFOX6. The objective regression rates were 50.00% and 58.33%, and the pathological complete response rates were 6.25% and 8.33%, respectively, in the CapeOX and mFOLFOX6 groups. Patients who received mFOLFOX6 had a better tumor regression grade (TRG) than those who received CapeOX (P = 0.005). Patients in both groups had similar survival outcomes.

CONCLUSIONS

The nCT has shown promising tumor response and survival outcomes, which can be a treatment option for baseline resectable LARC. For the two regimens, mFOLFOX6 provided better TRG than CapeOX, although no differences were observed in disease-free survival and OS.

Neoadjuvant chemotherapy for treatment patients with rectal cancer with adverse prognostic factors: A review

Rectal cancer (RC) is one of the leading tumor location in the structure of the incidence of malignant neoplasms in the Russian Federation and the world. And the standard approach to the treatment of patients with locally advanced forms of RC is preoperative chemo-radiotherapy (CRT) with delayed surgery. The use of such sort of approach in the recent decades has led to the reduction of the frequency of local recurrence up to 10% and even less. However, approximately a third of patients die of distant metastases. In this regard, one of the main tasks in the treatment of patients with locally advanced forms of RC with adverse prognostic factors is the prevention of distant metastasis formation. Early initiation of the systemic therapy before surgery is aimed at solving this issue. Conducting neoadjuvant chemotherapy (NCT) instead of CRT in RC treatment allows to avoid radiation reactions and injuries, occurring in some patients. Two-component oxaliplatin-containing regimens are the most well studied types of NCT in the treatment of patients with non-metastatic RC. In this connection, despite the differences in the treatment regimens and the number of cycles, a good tolerability of the method as well as no effect on the frequency of postoperative complications and in general a satisfactory results comparable to the effects of CRT were observed. The use of NCT in combination with targeted treatment modalities as well as three-component chemotherapy regimens are promising and encouraging treatment options for patients with RC with adverse prognostic factors.

Prolonged neoadjuvant chemotherapy without radiation versus total neoadjuvant therapy for locally advanced rectal cancer: A propensity score matched study

Background

Although neoadjvuant chemoradiotherapy (CRT) improves the local control rate of locally advanced rectal cancer (LARC), it fails to significantly improve disease-free survival (DFS) and overall survival (OS). We explored the efficacy of prolonged neoadjuvant chemotherapy (pNCT) without radiation and compared this schema with total neoadjuvant therapy (TNT).

Material and methods

Patients diagnosed with LARC and received TNT (4 cycles of induction CapeOX/FOLFOX followed with CRT) or pNCT (6~8 cycles of CapeOX/FOLFOX) between June 2016 and October 2021 were retrospective analyzed. All patients underwent total mesorectal excision (TME). A 1:1 propensity score match was performed to adjust baseline potential confounders. The tumor response, toxicity, recurrence-free survival (RFS) and OS were observed.

Results

A total of 184 patients with 92 patients in each group were finally enrolled. The median follow-up time was 35 months. TNT showed better pathological complete response (pCR) rate (25.0% vs 16.3%) and objective regression rate (73.9% vs 59.8%) than pNCT. TNT and pNCT produce similar 3-year RFS and OS rates in patients with mid-to-upper rectal cancer. TNT was associated with improved tumor responsiveness in all patients and improved 3-year RFS rates in those with low rectal cancer.

Conclusion

pNCT is an option for patients with mid-to-upper rectal cancer, but radiation is still necessary for low rectal cancer. To determine optimal schema for neoadjuvant therapy and patient selection, additional randomized controlled studies are needed.

Biologics in rectal cancer

INTRODUCTION

Despite the use of multimodality therapy, locally advanced rectal cancer (LARC) still presents high rates of disease recurrence. Fluoropyrimidine-based chemotherapy concurrently with radiation therapy (RT) remains the cornerstone of neoadjuvant therapy of LARC, and novel therapies are urgently needed in order to improve the clinical outcomes.

AREAS COVERED

We aim to summarize data from completed and ongoing clinical trials addressing the role of biological therapies, including monoclonal antibodies, immune checkpoint inhibitors (ICIs), antibody-drug conjugates, bispecific antibodies, and gene therapies in the systemic therapy of rectal cancer.

EXPERT OPINION

Deeper understanding of the molecular biology of colorectal cancer (CRC) has allowed meaningful advances in the systemic therapy of metastatic disease in the past few years. The larger applicability of biological therapy in CRC, including genome-guided targeted therapy, antiangiogenics, and immunotherapy, gives us optimism for the personalized management of rectal cancer. Microsatellite instability (MSI) tumors have demonstrated high sensitivity to ICIs, and preliminary findings in the neoadjuvant setting of rectal cancer are promising. To date, antiangiogenic and anti-EGFR therapies in LARC have not demonstrated the same benefit seen in metastatic disease. The outstanding results accomplished by biomarker-guided therapy in metastatic CRC will guide future developments of biological therapy in LARC.

Development and External Validation of a Preoperative Nomogram for Predicting Lateral Pelvic Lymph Node Metastasis in Patients With Advanced Lower Rectal Cancer

Background

The preoperative prediction of lateral pelvic lymph node (LPLN) metastasis is crucial in determining further treatment strategies for advanced lower rectal cancer patients. In this study, we established a nomogram model to preoperatively predict LPLN metastasis and then externally validated the accuracy of this model.

Methods

A total of 287 rectal cancer patients who underwent LPLN dissection were included in this study. Among them, 200 patients from the Peking University First Hospital were included in the development set, and 87 patients from the First Affiliated Hospital of Xi’an Jiaotong University were included in the independent external validation set. Multivariate logistic regression analysis was used to develop the nomogram. The performance of the nomogram was assessed based on its calibration, discrimination, and clinical utility.

Results

Five factors (differentiation grade, extramural vascular invasion, distance of the tumor from the anal verge, perirectal lymph node status, and largest short-axis diameter of LPLN) were identified and included in the nomogram. The nomogram developed based on the analysis showed robust discrimination with an area under the receiver operating characteristic curve (AUC) of 0.878 (95% CI, 0.824–0.932). The validation set showed good discrimination with an AUC of 0.863 (95% CI, 0.779–0.948). Decision curve analysis showed that the nomogram was clinically useful.

Conclusions

The present study proposed a clinical-imaging nomogram with a combination of clinicopathological risk factors and imaging features. After external verification, the predictive power of the nomogram model was satisfactory, and it is expected to be a convenient, visual, and personalized clinical tool for assessing the risk of LPLN metastasis in advanced lower rectal cancer patients.

Non-Operative Management of Patients with Rectal Cancer: Lessons Learnt from the OPRA Trial

Over the past decade, the management of locally advanced rectal cancer (LARC) has progressively become more complex. The introduction of total neoadjuvant treatment (TNT) has increased the rates of both clinical and pathological complete response, resulting in excellent long-term oncological outcomes. As a result, non-operative management (NOM) of LARC patients with a clinical complete response (cCR) after neoadjuvant therapy has gained acceptance as a potential treatment option in selected cases. NOM is based on replacement of surgical resection with safe and active surveillance. However, the identification of appropriate candidates for a NOM strategy without compromising oncologic safety is currently challenging due to the lack of an objective standardization. NOM should be part of the treatment plan discussion with LARC patients, considering the increasing rates of cCR, patient preference, quality of life, expectations, and the potential avoidance of surgical morbidity. The recently published OPRA trial showed that organ preservation is achievable in half of rectal cancer patients treated with TNT, and that chemoradiotherapy followed by consolidation chemotherapy may an appropriate strategy to maximize cCR rates. Ongoing trials are investigating optimal algorithms of TNT delivery to further expand the pool of patients who may benefit from NOM of LARC.

Short-term outcomes of neoadjuvant chemotherapy with capecitabineplus oxaliplatin for patients with locally advanced rectal cancerfollowed by total or tumor-specific mesorectal excision with orwithout lateral pelvic lymph node dissection

Background: The standard strategy in Japan for locally advanced rectal cancer is total mesorectal excision plus adjuvant chemotherapy. However, large tumors significantly restrict pelvic manipulation of the distal side of the tumor during surgery; therefore, from an oncological point of view, it is better to shrink the tumor as much as possible preoperatively to optimize the circumferential resection margin. In recent years, advances in systemic chemotherapy have significantly improved the tumor reduction effect, enabling such drug therapy prior to surgery for locally advanced rectal cancer. We herein retrospectively evaluated the clinical, short-term outcomes of patients treated by neoadjuvant chemotherapy (NAC) using capecitabin and oxaliplatin (CAPOX), focusing on overall safety as well as clinical and pathological staging responses to NAC.

Methods: We applied the preoperative chemotherapy protocol to T3-4, any N, M0 or M1a (with resectable metastases) (UICC 8^th) Ra/Rb rectal cancers. The chemotherapy regimen consisted of four cycles of CAPOX. After NAC, curative intent surgery with total mesorectal excision/tumor-specific mesorectal excision with/without metastasectomy was performed. Adverse effects (AEs) and compliance with NAC, surgical complications, clinical and pathological staging were evaluated. All patients undergoing the protocol between January 2017 and June 2021 at Fukushima Medical University were enrolled.

Results: Twenty cases were enrolled. No severe AEs were observed either preoperatively or perioperatively. Preoperative assessment of NAC showed no cases of progressive disease (PD). Radical resection was achieved in all cases. Histological therapeutic grading after NAC revealed one grade 3, four grade 2, three grade 1b, eleven grade 1a and one grade 0 among all cases.

Conclusion: This study suggests that NAC for locally advanced rectal cancer is likely to be acceptable because there were no severe AEs pre- or perioperatively, radical resection was achieved in all cases, and there were no cases of PD.

A randomized controlled trial comparing perioperative vs. postoperative mFOLFOX6 for lower rectal cancer with suspected lateral pelvic lymph node metastasis (JCOG1310): a phase II/III randomized controlled trial

Objective

The optimal perioperative chemotherapy for lower rectal cancer with lateral pelvic lymph node metastasis remains unclear. We evaluated the efficacy and safety of perioperative mFOLFOX6 in comparison with postoperative mFOLFOX6 for rectal cancer patients undergoing total mesorectal excision with lateral lymph node dissection.

Methods

We conducted an open label randomized phase II/III trial in 18 Japanese institutions. We enrolled patients with histologically proven lower rectal adenocarcinoma with clinical pelvic lateral lymph node metastasis who were randomly assigned (1:1) to receive postoperative mFOLFOX6 (12 courses of intravenous oxaliplatin [85 mg/m²] with L-leucovorin [200 mg/m²] followed by 5-fluorouracil [400 mg/m², bolus and 2400 mg/m², continuous infusion, repeated every 2 weeks]) or perioperative mFOLFOX6 (six courses each preoperatively and postoperatively). The primary endpoint was overall survival (OS). The trial is registered with Japan Registry of Clinical Trials, number jRCTs031180230.

Results

Between May 2015, and May 2019, 48 patients were randomized to the postoperative arm (n = 26) and the perioperative arm (n = 22). The trial was terminated prematurely due to poor accrual. The 3-year OS in the postoperative and perioperative groups were 66.1 and 84.4%, respectively (HR 0.58, 95% CI [0.14–2.45], one-sided P = 0.23). The pathological complete response rate in the perioperative group was 9.1%. Grade 3 postoperative surgical complications were more frequently observed in the perioperative arm (50.0 vs. 12.0%). One treatment-related death due to sepsis from pelvic infection occurred in the postoperative group.

Conclusions

Perioperative mFOLFOX6 may be an insufficient treatment to improve survival of lower rectal cancer with lateral pelvic lymph node metastasis.

The Multimodal Management of Locally Advanced Rectal Cancer: Making Sense of the New Data

In the past 40 years, the treatment of locally advanced rectal cancer has evolved with the addition of radiotherapy or chemoradiotherapy and providing (neo)adjuvant systemic chemotherapy to major surgery. However, recent trends have focused on improving our ability to risk-stratify patients and tailoring treatment to achieve the best oncologic outcome while limiting the impact on long-term quality of life. Therefore, there has been increasing interest in pursuing a watch-and-wait approach to achieve organ preservation. Several retro- and prospective studies suggest safety of the watch-and-wait approach, though it is still considered controversial due to limited clinical evidence, concerns about tumor regrowth, and subsequent distant progression. To further reduce treatment, MRI risk stratification, together with patient characteristics and patient preferences, can guide personalized treatment and reserve radiation and chemotherapy for a select patient population. Ultimately, improved options for reassessment during neoadjuvant treatment may allow for more adaptive therapy options based on treatment response. This article provides an overview of some major developments in the multimodal treatment of locally advanced rectal cancer. It reviews some relevant, controversial issues of the watch-and-wait approach and opportunities to personally tailor and reduce treatment. It also reviews the overall neoadjuvant treatment, including total neoadjuvant therapy trials, and how to best optimize for a potential complete response. Finally, it provides an algorithm as an example of how such a personalized, tailored, adaptive, and reduced treatment could look like in the future.

Nonoperative Management for Rectal Cancer

The treatment algorithm for locally advanced rectal cancer (LARC) has increased in complexity over the past 10 years. Nonoperative management (NOM) for rectal cancer in patients with clinical complete response (cCR) after neoadjuvant therapy has been gaining acceptance as a potential treatment option for selected LARC patients. The current challenge is to accurately select the patients with an apparent cCR, thereby correctly identifying those would-be appropriate candidates for a NOM strategy. NOM should be part of the treatment discussion of LARC, considering increasing rates of cCR, patient preference, potential quality of life gains, and the potential avoidance of surgical morbidity.

Survival After Induction Chemotherapy and Chemoradiation Versus Chemoradiation and Adjuvant Chemotherapy for Locally Advanced Rectal Cancer

BACKGROUND

Total neoadjuvant therapy (TNT) improves tumor response in locally advanced rectal cancer (LARC) patients compared to neoadjuvant chemoradiotherapy alone. The effect of TNT on patient survival has not been fully investigated.

MATERIALS AND METHODS

This was a retrospective case series of patients with LARC at a comprehensive cancer center. Three hundred and eleven patients received chemoradiotherapy (chemoRT) as the sole neoadjuvant treatment and planned adjuvant chemotherapy, and 313 received TNT (induction fluorouracil and oxaliplatin-based chemotherapy followed by chemoradiotherapy in the neoadjuvant setting). These patients then underwent total mesorectal excision or were entered in a watch-and-wait protocol. The proportion of patients with complete response (CR) after neoadjuvant therapy (defined as pathological CR or clinical CR sustained for 2 years) was compared by the χ2 test. Disease-free survival (DFS), local recurrence-free survival, distant metastasis-free survival, and overall survival were assessed by Kaplan-Meier analysis and log-rank test. Cox regression models were used to further evaluate DFS.

RESULTS

The rate of CR was 20% for chemoRT and 27% for TNT (P=.05). DFS, local recurrence-free survival, metastasis-free survival, and overall survival were no different. Disease-free survival was not associated with the type of neoadjuvant treatment (hazard ratio [HR] 1.3; 95% confidence interval [CI] 0.93-1.80; P = .12).

CONCLUSIONS

Although TNT does not prolong survival than neoadjuvant chemoradiotherapy plus intended postoperative chemotherapy, the higher response rate associated with TNT may create opportunities to preserve the rectum in more patients with LARC.

Robotic surgery contributes to the preservation of bowel and urinary function after total mesorectal excision: comparisons with transanal and conventional laparoscopic surgery

BACKGROUND

Determine whether robotic surgery is more effective than transanal and conventional laparoscopic surgery in preserving bowel and urinary function after total mesorectal excision (TME).

METHODS

Of 79 lower rectal cancer patients who underwent function-preserving TME between 2016 and 2020, 64 patients consented to a prospective questionnaire-based functional observation study (52 responded). At 6 months post-resection or ileostomy closure, Wexner, low anterior resection syndrome (LARS), modified fecal incontinence quality of life, and international prostate symptom scores were used to evaluate bowel and urinary function, comparing robotic surgery (RTME) with transanal (taTME) or conventional laparoscopic surgery (LTME).

RESULTS

RTME was performed in 35 patients (54.7%), taTME in 15 (23.4%), and LTME in 14 (21.9%). While preoperative bowel/urinary functions were similar in all three procedures, and the distance from the anal verge to tumor was almost the same, more hand-sewn anastomoses were performed and the anastomotic height from the anal verge was shorter in taTME than RTME. At 2 years post-resection, 8 patients (12.5%) had a permanent stoma; RTME showed a significantly lower rate of permanent stoma than taTME (2.9% vs. 40%, p < 0.01). Despite no significant difference, all bowel function assessments were better in RTME than in taTME or LTME. Major LARS was observed in all taTME and LTME cases, but only 78.8% of RTME. No clear difference arose between RTME and taTME in urinary function; urinary dysfunction was more severe in LTME than RTME (36.4% vs. 6.1%, p = 0.02).

CONCLUSIONS

In function-preserving TME for lower rectal cancer, robotic surgery was suggested to be more effective than transanal and conventional laparoscopic surgery in terms of bowel and urinary functions.

Determining Which Patients Require Preoperative Pelvic Radiotherapy Before Curative-Intent Surgery and/or Ablation for Metastatic Rectal Cancer

BACKGROUND

The aim of this study is to determine the optimal indications for preoperative pelvic radiotherapy (RT) in patients with metastatic rectal cancer who underwent curative-intent surgical resection and/or ablation.

METHODS

Between January 2000 and October 2019, 246 patients who met our inclusion criteria were enrolled. Preoperative RT was performed in 22 patients (8.9%). Lower margin below the peritoneal reflection (p < 0.001), mesorectal fascia (MRF) invasion (p = 0.02), and lateral pelvic lymph node (LPLN) involvement (p = 0.005) were more frequent in the preoperative RT group.

RESULTS

During the median follow-up period of 13.3 months (interquartile range [IQR]: 6.0-36.3 months), local recurrence (LR) was identified in 60 patients (24.4%). It was the first site of recurrence in 45 of them (18.3%). Among them, three patients were in the preoperative RT group. On multivariable analysis, lower margin below the peritoneal reflection, MRF invasion, LPLN involvement, carcinoembryonic antigen (CEA) level ≥ 10 ng/mL before treatment, and preoperative RT were significant prognostic factors for LR-free survival (LRFS). In the patient group without any risk factors, the 2-year LRFS rate was 94.9% without preoperative RT. In the patient group with one or more risk factors, the 2-year LRFS was 64.4% without and 95.2% with preoperative RT.

CONCLUSION

LR developed in about 25% of patients within 2 years. Preoperative RT should be considered, especially in patients with a risk factor for LR, including lower margin below the peritoneal reflection, MRF invasion, LPLN involvement, or CEA ≥ 10 ng/mL before treatment.

Neoadjuvant Therapy for Rectal Cancer

The treatment of locally advanced rectal cancer is challenging and requires a multidisciplinary approach. Neoadjuvant treatment has improved local control by the combination of radiotherapy, surgery, and chemotherapy. However, neoadjuvant treatment has not yet been shown to improve overall survival and is associated with toxicities and late sequelae that impair the quality of life of patients. Currently, different types of neoadjuvant strategies have raised the question about which one is the optimal strategy for rectal cancer treatment. In this article, we explore the different neoadjuvant treatment regimens currently available, their associated benefits and toxicities, and novel approaches in this area.

The Evolving Neoadjuvant Treatment Paradigm for Patients with Locoregional mismatch Repair Proficient Rectal Cancer

OPINION STATEMENT

The standard of care for locally advanced rectal cancer (LARC) has included preoperative chemoradiation, total mesorectal excision surgery and post operative adjuvant chemotherapy based on histopathology. The current therapeutic landscape in LARC has many different options with different directions of travel - depending on the goal of treatment. Enthusiasm for delivering total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is increasing in the light of recently published randomised phase III trials - RAPIDO and PRODIGE-23. There is a wide diversity of different potential schedules and a multitude of approaches, which include induction neoadjuvant chemotherapy (NACT) with a range of chemotherapy options (CAPEOX, FOLFOX, FOLFOXIRI) and a varying duration of 6-18 weeks, or consolidation NACT. These schedules either precede or follow short-course preoperative radiation therapy (SCPRT) using 5 × 5Gy or long-course chemoradiation (LCCRT) using 45-60Gy respectively. The different strategies of induction and consolidation neoadjuvant chemotherapy have been compared and have similar long-term outcomes, but consolidation chemotherapy may facilitate organ-sparing. The results are driving novel paradigms with both intensification and de-intensification treatment strategies. The ideal combination, sequence or duration of such a TNT approach remains undefined. As yet, there are no robust clinical, genetic, molecular, immune or imaging features (alone or integrated), which either direct or aid these choices. Currently, the selection of neoadjuvant treatment is driven by the impact on avoidance or feasibility of surgery or reducing the risk of metastases rather than prevention of local recurrence. Most believe that TNT will improve overall survival, despite the present lack of evidence. Both the inherent heterogeneity in LARC and the observed range of different responses underline the need for response biomarkers to individually tailor therapy rather than 'a one size fits all' approach.

Short-Term Outcomes with Standardized Transperineal Minimally Invasive Abdominoperineal Excision for Rectal Cancer

BACKGROUND

Transperineal abdominoperineal excision (TpAPE) is an emerging approach for low rectal cancers but is technically challenging. Based on an anatomical study we conducted previously, we have standardized the TpAPE procedure. Here, we aimed to validate the feasibility of the standardized TpAPE by investigating the short-term outcomes.

METHODS

From January 2018 to November 2020, a total of 405 patients underwent laparoscopic or robotic rectal resection for rectal cancer in our institution. For the current study, we analyzed data for the 31 patients who underwent TpAPE. The abdominal phase was performed synchronously with the perineal phase using either a laparoscopic or robotic approach. Short-term outcomes included operative and pathological results.

RESULTS

Of the 31 cases, we identified anterior quadrant tumor invasion in 21. Most of the cases were advanced, with 6 staged as cT3 and 20 as T4. Of the 27 cases not involving distant metastasis, neoadjuvant therapy was performed in 19. No inadvertent rectal perforation or urethral injury was found intraoperatively. The median procedural duration to specimen removal was 250 min (interquartile range, 204-287), and the median intraoperative blood loss was 10 ml (interquartile range, 5-40). Regarding postoperative complications, perineal wound infection developed in 11 cases. A positive circumferential resection margin was found in 3, corresponding to the positive rate of 9.7%. These three cases were among the first 12 cases involving standardized TpAPE.

CONCLUSIONS

The current results indicate that TpAPE can be performed safely and might represent a useful option for low rectal cancer resection.

Predictive value of serum alpha-fetoprotein for tumor regression after preoperative chemotherapy for rectal cancer

BACKGROUND

Preoperative therapy is widely used in locally advanced rectal cancer. It can improve local control of rectal cancer. However, there are few indicators that can predict the effect of preoperative chemotherapy accurately.

AIM

To investigate whether the increase in serum α-fetoprotein (AFP) can predict better efficacy of preoperative chemotherapy.

METHODS

This was a retrospective study. We analyzed 125 patients admitted between 2017 and 2019 with locally advanced rectal cancer. All patients received six cycles of preoperative chemotherapy (mFOLFOX6 every 2 wk). Serum AFP of 26 patients rose slightly after three or four cycles of chemotherapy, and fell to normal again within 2 mo. The other 99 patients had a normal level of serum AFP during chemotherapy. Patients were divided into two groups (AFP risen and AFP normal). According to postoperative pathology, we compared tumor regression and complete response rate between the two groups. The primary outcome measure was the tumor regression grade (TRG) after chemotherapy. The difference in pathological complete response between the two groups was also investigated.

RESULTS

There were no tumor progression and distant metastasis in both groups during preoperative chemotherapy. Patients in the AFP risen group achieved better TRG 0/1 than those in the AFP normal group (61.5% vs 39.4%). The increase in AFP was a significant predictor for better tumor regression [χ² = 4.144, odds ratio (OR) = 2.666, P = 0.04]. In the AFP risen group, the complete response rate was 30.8%, which was higher than in the AFP normal group (30.8% vs 12.1%, χ² = 4.542, OR = 3.251, P = 0.03).

CONCLUSION

Patients with a slight increase in serum AFP can achieve better tumor regression during preoperative chemotherapy, and are more likely to achieve pathological complete response.

Long-Term Outcome in a Phase II Study of Regional Hyperthermia Added to Preoperative Radiochemotherapy in Locally Advanced and Recurrent Rectal Adenocarcinomas

Hyperthermia was added to standard preoperative chemoradiation for rectal adenocarcinomas in a phase II study. Patients with T3-4 N0-2 M0 rectal cancer or local recurrences were included. Radiation dose was 54 Gy combined with capecitabine 825 mg/m2 × 2 daily and once weekly oxaliplatin 55 mg/m2. Regional hyperthermia aimed at 41.5–42.5 °C for 60 min combined with oxaliplatin infusion. Radical surgery with total or extended TME technique, was scheduled at 6–8 weeks after radiation. From April 2003 to April 2008, a total of 49 eligible patients were recruited. Median number of hyperthermia sessions were 5.4. A total of 47 out of 49 patients (96%) had the scheduled surgery, which was clinically radical in 44 patients. Complete tumour regression occurred in 29.8% of the patients who also exhibited statistically significantly better RFS and CSS. Rate of local recurrence alone at 10 years was 9.1%, distant metastases alone occurred in 25.6%, including local recurrences 40.4%. RFS for all patients was 54.8% after 5 years and CSS was 73.5%. Patients with T50 temperatures in tumours above median 39.9 °C had better RFS, 66.7% vs. 31.3%, p = 0.047, indicating a role of hyperthermia. Toxicity was acceptable.

Locally Advanced Rectal Cancer: What We Learned in the Last Two Decades and the Future Perspectives

The advancement in surgical techniques, optimization of systemic chemoradiotherapy, and development of refined diagnostic and imaging modalities have brought a phenomenal shift in the treatment of the locally advanced rectal cancer. Although each therapeutic option has shown substantial progress in their field, it is finding their ideal amalgamation which has baffled the clinician and researchers alike. In the effort to identifying the perfect salutary treatment plan, we have even shifted our attention from the trimodal approach to non-operative "watchful waiting" to more recent individualized care. In this article, we acknowledge the scientific progress in the management of locally advanced rectal cancer and compare the opportunities as well as the obstacles while implementing them clinically. We also explore the current challenges and controversies surrounding the multidisciplinary approach and highlight the new trends and recent advances with an ultimate goal to improve the patients' quality of life.

Pathological complete response after neoadjuvant chemotherapy with FOLFOX for locally advanced sigmoid colon cancer with diverticulitis: A case report

Introduction and importance

The standard treatment for locally advanced colon cancer (LACC) without distant metastasis is curative surgery followed by adjuvant chemotherapy, but the long-term outcomes of this strategy are not satisfactory. Neoadjuvant chemotherapy (NAC) is a promising novel option to overcome this issue. Tumor regression is an expected effect of NAC for LACC, but pathological complete response (pCR) is rare. In this report, we present a rare case of pCR after NAC with FOLFOX for LACC in the sigmoid colon.

Presentation of case

A 66-year-old woman presented to our hospital with fever and abdominal pain. The diagnosis was LACC in the sigmoid colon with possible invasion of the uterus and pelvic wall, stage IIIC (T4bN1bM0). Furthermore, the tumor was complicated by diverticulitis. A colostomy was performed, followed by NAC with FOLFOX. Six cycles were completed without significant adverse events, and the lesion shrunk remarkably. We performed a curative sigmoidectomy without any postoperative complications. Pathological examination revealed no viable cancer cells, indicating pCR.

Discussion

To the best of our knowledge, this is the first report of pCR after NAC for LACC complicated by diverticulitis. Colostomy before NAC, regimen, and cycle of NAC may be the key to this favorable course.

Conclusion

We present a rare case of pathological complete after neoadjuvant chemotherapy with FOLFOX for locally advanced colon cancer in the sigmoid colon complicated by diverticulitis. Our experience may be valuable in determining the optimal treatment strategy for LACC complicated by diverticulitis.

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Neoadjuvant chemotherapy is a promising novel option for locally advanced colon cancer.

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Pathological complete response is rare.

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Indications for cases complicated with diverticulitis are unknown.

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We present a rare case of pCR after NAC for LACC complicated by diverticulitis.

Neoadjuvant Chemotherapy plus Bevacizumab Combined with Total Mesorectal Excision in Treating Locally Advanced Rectal Cancer Patients with BRAF Mutation: Clinical Benefit and Safety

Objective

To investigate clinical benefit and safety of neoadjuvant chemotherapy (NAC) plus bevacizumab combined with total mesorectal excision (TME) in treating patients with BRAF-mutated locally advanced rectal cancer (LARC).

Methods

This study included LARC patients with BRAF mutation admitted to the Oncology Department of Fujian Medical University Cancer Hospital, Fujian Cancer Hospital, between June 2013 and December 2018. Patients in the control group received a standard treatment regimen of TME combined with NAC (n = 45), and patients in the observation group received NAC plus bevacizumab combined with TME (n = 55). The short-term clinical efficacy of the two groups after NAC treatment was observed and compared, including differences in the pathological downstaging rate. The incidence of perioperative complications and adverse reactions during neoadjuvant therapy was compared to evaluate the safety of the treatment. Besides, the relapse-free survival (RFS) and overall survival (OS) of patients were analyzed to evaluate the long-term clinical benefit of the treatment.

Results

Compared with the control group, the ypT staging rate (p = 0.014) in the observation group was markedly lower. In addition, patients in the observation group had a prominently lower overall incidence of complications (p < 0.001) during the perioperative period and a remarkably lower incidence of leukopenia (p = 0.037) during neoadjuvant therapy. In terms of long-term clinical benefit, the RFS of patients in the observation group was evidently longer (p = 0.037) than that in the control group.

Conclusion

Compared with TME plus NAC treatment, the short-term and long-term clinical benefits are higher and safety is more favorable of NAC plus bevacizumab combined with TME in treating LARC patients.

Rectal cancer: Maximizing local control and minimizing toxicity

Adoption of multimodality treatment approach for rectal cancer has resulted in significant improvements in oncologic outcomes. The roles of chemotherapy, radiation, and surgery in rectal cancer treatment are continuously evolving with the goal of achieving the best possible oncologic and functional outcome while minimizing treatment toxicity. The aim of this review is to summarize the most recent trials focusing on organ-sparing treatment strategies and the optimal selection of patients for neoadjuvant radiation therapy.

Concurrent use of statins and neoadjuvant chemoradiotherapy for rectal cancer: a systematic review and meta-analysis

PURPOSE

Statins are used primarily in patients with cardiovascular disease. More recently, they have demonstrated benefit in oncology patients. In vitro models have shown decreased rectal tumor cell viability in cells receiving chemoradiation and statin therapy. In vivo models have been less clear. This study aims to elucidate the impact of concurrent use of statins on the efficacy of neoadjuvant therapy for rectal cancer.

METHODS

Search of Medline, EMBASE, and CENTRAL was performed. Articles were included if they reported complete pathological response (pCR), long-term oncologic outcomes, or chemoradiotherapy-induced toxicity in patients with rectal cancer receiving concurrent statin and neoadjuvant therapy. A pairwise meta-analyses was performed using inverse variance random effects.

RESULTS

From 1564 citations, six studies with 726 patients on statin therapy (24.5% female, age: 63.6 years) and 1863 patients not on statin therapy (35.6% female, age: 60.9 years) were included. There was no significant difference in pCR rate between patients on statin therapy and patients not on statin therapy (RR 1.23, 95%CI 0.98-1.54, p = 0.08). Similarly, no difference existed between groups in long-term oncologic outcomes (5-year overall survival: RR 1.03, 95%CI 0.86-1.24, p = 0.75; 5-year disease-free survival: RR 1.04, 95%CI 0.85-1.26, p = 0.73). Chemoradiotherapy-induced toxicities were similar between groups.

CONCLUSION

The concurrent use of statin and neoadjuvant therapy did not significantly impact short- or long-term oncologic outcomes in patients with rectal cancer. Yet, despite pooling of data, this study remained inadequately powered. Larger, prospective studies are required to further elucidate the impact of statins on patients undergoing neoadjuvant therapy for rectal cancer.