Time Interval Between the End of Neoadjuvant Therapy and Elective Resection of Locally Advanced Rectal Cancer in the CRONOS Study

Short-term outcomes of short- and long-course chemoradiotherapy before total mesorectal excision for locally advanced rectal tumors: A single-center study in Taiwan utilizing propensity score matching

BACKGROUND

Locally advanced rectal tumors are typically treated with neoadjuvant chemoradiotherapy. Short-course chemoradiotherapy (SCRT, 2500 cGy in five fractions) is a convenient alternative to concurrent chemoradiotherapy with long-course radiotherapy (CCRT, 4500 cGy in 25 fractions) without sacrificing efficacy. We aimed to compare the short-term outcomes of SCRT and CCRT in patients with mid- and low- rectal tumors who underwent total mesorectal excision using real-world data.

METHODS

We retrospectively reviewed the data of patients with locally advanced rectal cancer who underwent radical resection after neoadjuvant chemoradiotherapy from 2011 to 2022. We analyzed the clinicopathological findings and prognostic factors for disease-free and overall survival in the SCRT and CCRT groups and compared the outcomes using propensity score matching.

RESULTS

Among the 66 patients in the two groups, no disparities were noted in the demographic features, pathological remission, or downstaging rates. Nonetheless, the SCRT group exhibited superior 3-year disease-free survival (81.8% vs 62.1%, p = 0.011), whereas the overall survival did not differ significantly between the two groups. The initial carcinoembryonic antigen (CEA) levels and neoadjuvant SCRT were associated with the recurrence rates [hazard ratio (HR) = 1.13-4.10; HR = 0.19-0.74], but the harvested lymph node count was not (HR = 0.51-1.97).

CONCLUSION

Among patients with locally advanced rectal cancer, SCRT combined with four cycles of FOLFOX was shown to enhance short-term disease-free survival. Factors impacting recurrence include the initial CEA level and SCRT, but not the harvested lymph node count.

Factors influencing pathological complete response and tumor regression in neoadjuvant radiotherapy and chemotherapy for high-risk breast cancer

BACKGROUND

Pathological complete response (pCR) is a well-established prognostic factor in breast cancer treated with neoadjuvant systemic therapy (naST). The determining factors of pCR are known to be intrinsic subtype, proliferation index, grading, clinical tumor and nodal stage as well as type of systemic therapy. The addition of neoadjuvant radiotherapy (naRT) to this paradigm might improve response, freedom from disease, toxicity and cosmetic outcome compared to adjuvant radiotherapy. The factors for pCR and primary tumor regression when neoadjuvant radiation therapy is added to chemotherapy have not been thoroughly described.

METHODS

We performed a retrospective analysis of 341 patients (cT1-cT4/cN0-N+) treated with naRT and naST between 1990 and 2003. Patients underwent naRT to the breast and mostly to the supra-/infraclavicular lymph nodes combined with an electron or brachytherapy boost. NaST was given either sequentially or simultaneously to naRT using different regimens. We used the univariate and multivariate regression analysis to estimate the effect of different subgroups and treatment modalities on pCR (ypT0/Tis and ypN0) as well as complete primary tumor response (ypT0/Tis; bpCR) in our cohort. Receiver operating characteristic (ROC) analysis was performed to evaluate the interval between radiotherapy (RT) and resection (Rx) as well as radiotherapy dose.

RESULTS

Out of 341 patients, pCR and pbCR were achieved in 31% and 39%, respectively. pCR rate was influenced by resection type, breast cancer subtype, primary tumor stage and interval from radiation to surgery in the multivariate analysis. Univariate analysis of bpCR showed age, resection type, breast cancer subtype, clinical tumor stage and grading as significant factors. Resection type, subtype and clinical tumor stage remained significant in multivariate analysis. Radiation dose to the tumor and interval from radiation to surgery were not significant factors for pCR. However, when treatment factors were added to the model, a longer interval from radiotherapy to resection was a significant predictor for pCR.

CONCLUSIONS

The factors associated with pCR following naST and naRT are similar to known factors after naST alone. Longer interval to surgery might to be associated with higher pCR rates. Dose escalation beyond 60 Gy did not result in higher response rates.

Prediction of pathological complete response and prognosis in locally advanced rectal cancer

BACKGROUND

Colorectal cancer is currently the third most common malignant tumor and the second leading cause of cancer-related death worldwide. Neoadjuvant chemoradiotherapy (nCRT) is standard for locally advanced rectal cancer (LARC). Except for pathological examination after resection, it is not known exactly whether LARC patients have achieved pathological complete response (pCR) before surgery. To date, there are no clear clinical indicators that can predict the efficacy of nCRT and patient outcomes.

AIM

To investigate the indicators that can predict pCR and long-term outcomes following nCRT in patients with LARC.

METHODS

Clinical data of 128 LARC patients admitted to our hospital between September 2013 and November 2022 were retrospectively analyzed. Patients were categorized into pCR and non-pCR groups. Univariate analysis (using the χ² test or Fisher’s exact test) and logistic multivariate regression analysis were used to study clinical predictors affecting pCR. The 5-year disease-free survival (DFS) and overall survival (OS) rates were calculated using Kaplan-Meier analysis, and differences in survival curves were assessed with the log-rank test.

RESULTS

Univariate analysis showed that pretreatment carcinoembryonic antigen (CEA) level, lymphocyte-monocyte ratio (LMR), time interval between neoadjuvant therapy completion and total mesorectal excision, and tumor size were correlated with pCR. Multivariate results showed that CEA ≤ 5 ng/mL (P = 0.039), LMR > 2.73 (P = 0.023), and time interval > 10 wk (P = 0.039) were independent predictors for pCR. Survival analysis demonstrated that patients in the pCR group had significantly higher 5-year DFS rates (94.7% vs 59.7%, P = 0.002) and 5-year OS rates (95.8% vs 80.1%, P = 0.019) compared to the non-pCR group. Tumor deposits (TDs) were significantly correlated with shorter DFS (P = 0.002) and OS (P < 0.001).

CONCLUSION

Pretreatment CEA, LMR, and time interval contribute to predicting nCRT efficacy in LARC patients. Achieving pCR demonstrates longer DFS and OS. TDs correlate with poor prognosis.

Prediction of pathological complete response and prognosis in locally advanced rectal cancer

BACKGROUND

Colorectal cancer is currently the third most common malignant tumor and the second leading cause of cancer-related death worldwide. Neoadjuvant chemoradiotherapy (nCRT) is standard for locally advanced rectal cancer (LARC). Except for pathological examination after resection, it is not known exactly whether LARC patients have achieved pathological complete response (pCR) before surgery. To date, there are no clear clinical indicators that can predict the efficacy of nCRT and patient outcomes.

AIM

To investigate the indicators that can predict pCR and long-term outcomes following nCRT in patients with LARC.

METHODS

Clinical data of 128 LARC patients admitted to our hospital between September 2013 and November 2022 were retrospectively analyzed. Patients were categorized into pCR and non-pCR groups. Univariate analysis (using the χ 2 test or Fisher's exact test) and logistic multivariate regression analysis were used to study clinical predictors affecting pCR. The 5-year disease-free survival (DFS) and overall survival (OS) rates were calculated using Kaplan-Meier analysis, and differences in survival curves were assessed with the log-rank test.

RESULTS

Univariate analysis showed that pretreatment carcinoembryonic antigen (CEA) level, lymphocyte-monocyte ratio (LMR), time interval between neoadjuvant therapy completion and total mesorectal excision, and tumor size were correlated with pCR. Multivariate results showed that CEA ≤ 5 ng/mL (P = 0.039), LMR > 2.73 (P = 0.023), and time interval > 10 wk (P = 0.039) were independent predictors for pCR. Survival analysis demonstrated that patients in the pCR group had significantly higher 5-year DFS rates (94.7% vs 59.7%, P = 0.002) and 5-year OS rates (95.8% vs 80.1%, P = 0.019) compared to the non-pCR group. Tumor deposits (TDs) were significantly correlated with shorter DFS (P = 0.002) and OS (P < 0.001).

CONCLUSION

Pretreatment CEA, LMR, and time interval contribute to predicting nCRT efficacy in LARC patients. Achieving pCR demonstrates longer DFS and OS. TDs correlate with poor prognosis.

Fibrosis signature of anastomotic margins for predicting anastomotic stenosis in rectal cancer with neoadjuvant chemoradiotherapy and sphincter-preserving surgery

Background

Radiation-induced colorectal fibrosis (RICF) is a common pathological alteration among patients with rectal cancer undergoing neoadjuvant chemoradiotherapy (nCRT). Anastomotic stenosis (AS) causes symptoms and negatively impacts patients' quality of life and long-term survival. In this study, we aimed to evaluate the fibrosis signature of RICF and develop a nomogram to predict the risk of AS in patients with rectal cancer undergoing nCRT.

Methods

Overall, 335 pairs of proximal and distal margins were collected and randomly assigned at a 7:3 ratio to the training and testing cohorts. The RICF score was established to evaluate the fibrosis signature in the anastomotic margins. A nomogram based on the RICF score for AS was developed and evaluated by using the area under the curve, decision curve analysis, and the DeLong test.

Results

The training cohort included 235 patients (161 males [68.51%]; mean age, 59.61 years) with an occurrence rate of AS of 17.4%, whereas the testing cohort included 100 patients (72 males [72.00%]; mean age, 57.17 years) with an occurrence rate of AS of 11%. The RICF total score of proximal and distal margins was significantly associated with AS (odds ratio, 3.064; 95% confidence interval [CI], 2.200-4.268; P < 0.001). Multivariable analysis revealed that the RICF total score, neoadjuvant radiotherapy, and surgical approach were independent predictors for AS. The nomogram demonstrated good discrimination in the training cohort (area under the receiver-operating characteristic curve, 0.876; 95% CI, 0.816-0.937), with a sensitivity of 68.3% (95% CI, 51.9%-81.9%) and a specificity of 85.5% (95% CI, 78.7%-89.3%). Similar results were observed in the testing cohort.

Conclusions

This study results suggest that the RICF total score of anastomotic margins is an independent predictor for AS. The prediction model developed based on the RICF total score may be useful for individualized AS risk prediction in patients with rectal cancer undergoing nCRT and sphincter-preserving surgery.

The m6A modification mediated-lncRNA POU6F2-AS1 reprograms fatty acid metabolism and facilitates the growth of colorectal cancer via upregulation of FASN

BACKGROUND

Long noncoding RNAs (lncRNAs) have emerged as key players in tumorigenesis and tumour progression. However, the biological functions and potential mechanisms of lncRNAs in colorectal cancer (CRC) are unclear.

METHODS

The novel lncRNA POU6F2-AS1 was identified through bioinformatics analysis, and its expression in CRC patients was verified via qRT-PCR and FISH. In vitro and in vivo experiments, such as BODIPY staining, Oil Red O staining, triglyceride (TAG) assays, and liquid chromatography mass spectrometry (LC-MS) were subsequently performed with CRC specimens and cells to determine the clinical significance, and functional roles of POU6F2-AS1. Biotinylated RNA pull-down, RIP, Me-RIP, ChIP, and patient-derived organoid (PDO) culture assays were performed to confirm the underlying mechanism of POU6F2-AS1.

RESULTS

The lncRNA POU6F2-AS1 is markedly upregulated in CRC and associated with adverse clinicopathological features and poor overall survival in CRC patients. Functionally, POU6F2-AS1 promotes the growth and lipogenesis of CRC cells both in vitro and in vivo. Mechanistically, METTL3-induced m6A modification is involved in the upregulation of POU6F2-AS1. Furthermore, upregulated POU6F2-AS1 could tether YBX1 to the FASN promoter to induce transcriptional activation, thus facilitating the growth and lipogenesis of CRC cells.

CONCLUSIONS

Our data revealed that the upregulation of POU6F2-AS1 plays a critical role in CRC fatty acid metabolism and might provide a novel promising biomarker and therapeutic target for CRC.

Retrospective analysis of preoperative application of triple-modal pre-rehabilitation on postoperative recovery of colorectal cancer patients

PURPOSE

To retrospectively analyze the difference between triple-modal pre-rehabilitation and common treatment in patients with colorectal cancer (CRC).

METHODS

A total of 145 patients with CRC diagnosed by pathology and admitted to our hospital for surgery between June 2020 and June 2022 were included in the study. All patients were divided into two groups: the triple-modal pre-rehabilitation group (pre-rehabilitation group) and the common treatment group. The triple-modal pre-rehabilitation strategy included exercise (3-5 times per week, with each session lasting more than 50 min), nutritional support, and psychological support. The study was designed to assess the potential of the pre-rehabilitation intervention to accelerate postoperative recovery by assessing the 6-min walk test, nutritional indicators, and HADS score before and after surgery.

RESULTS

The pre-rehabilitation intervention did not reduce the duration of initial postoperative recovery or the incidence of postoperative complications, but it did increase the patients' exercise capacity (as determined by the 6-min walk test), with the pre-rehabilitation group performing significantly better than the common group (433.0 (105.0) vs. 389.0 (103.5), P < 0.001). The study also found that triple-modal pre-rehabilitation was beneficial for the early recovery of nutritional status in surgical patients and improved anxiety and depression in patients after surgery, especially in those who had not received neoadjuvant therapy.

CONCLUSION

The triple-modal pre-rehabilitation strategy is of significant importance for reducing stress and improving the functional reserve of patients with colorectal cancer (CRC) during the perioperative period. The results of our study provide further support for the integration of the triple-modal pre-rehabilitation strategy into the treatment and care of CRC patients.

Surgical and local control outcomes after sequential short-course radiation therapy and chemotherapy for rectal cancer

Background

Total neoadjuvant therapy (TNT) is an accepted approach for the management of locally advanced rectal cancer (LARC) and is associated with a decreased risk of development of metastatic disease compared to standard neoadjuvant therapy. However, questions remain regarding surgical outcomes and local control in patients who proceed to surgery, particularly when radiation is given first in the neoadjuvant sequence. We report on our institution's experience with patients who underwent short-course radiation therapy, consolidation chemotherapy, and surgery.

Methods

We retrospectively reviewed surgical specimen outcomes, postoperative complications, and local/pelvic control in a large cohort of patients with LARC who underwent neoadjuvant therapy incorporating upfront short-course radiation therapy followed by consolidation chemotherapy.

Results

In our cohort of 83 patients who proceeded to surgery, a complete/near-complete mesorectal specimen was achieved in 90 % of patients. This outcome was not associated with the time interval from completion of radiation to surgery. Postoperative complications were acceptably low. Local control at two years was 93.4 % for all patients- 97.6 % for those with low-risk disease and 90.4 % for high-risk disease.

Conclusion

Upfront short-course radiation therapy and consolidation chemotherapy is an effective treatment course. Extended interval from completion of short-course radiation therapy did not impact surgical specimen quality.

Recent advances in rectal cancer treatment - are we on the right track?

Background

Staging and treatment of rectal cancer have evolved over several decades with considerably fewer locoregional recurrences but no marked improved survival since systemic recurrence risks remain virtually unchanged. This development will briefly be summarised followed by a thorough discussion of two recent developments.

Methods

A systematic approach towards the literature is aimed at focusing on organ preservation and the delivery of all non-surgical treatments prior to surgery or total neoadjuvant treatment (TNT).

Results

Organ preservation, that is to defer surgery if the tumour happens to disappear completely after any pre-treatment given to locally advanced tumours to decrease recurrence risks has increased in popularity and is, if not universally, widely accepted. To give neo-adjuvant treatment to intentionally obtain a clinically complete remission to avoid surgery is practised in some environments but is mostly still experimental. TNT, that is to provide both radiotherapy and chemotherapy aimed at killing microscopic disease in the pelvis or elsewhere has been subject to several trials. Collectively, they show that the chance of achieving a complete response, pathologically or clinically, has approximately doubled, increasing the chance for organ preservation, and the risk of distant metastasis has decreased at least in some trials. The best schedule remains to be established.

Conclusions

To obtain substantial progress and also improve survival, the systemic treatments need to be improved even if preoperative delivery is more effective and better tolerated than postoperative. The locoregional treatment may be further optimised through better risk prediction.

Phase II study of capecitabine-based concomitant chemoradiation followed by durvalumab as a neoadjuvant strategy in locally advanced rectal cancer: the PANDORA trial

BACKGROUND

This study investigated the efficacy of chemoradiotherapy (CRT) followed by durvalumab as neoadjuvant therapy of locally advanced rectal cancer.

PATIENTS AND METHODS

The PANDORA trial is a prospective, phase II, open-label, single-arm, multicenter study aimed at evaluating the efficacy and safety of preoperative treatment with durvalumab (1500 mg every 4 weeks for three administrations) following long-course radiotherapy (RT) plus concomitant capecitabine (5040 cGy RT in 25-28 fractions over 5 weeks and capecitabine administered at 825 mg/m2 twice daily). The primary endpoint was the pathological complete response (pCR) rate; secondary endpoints were the proportion of clinical complete remissions and safety. The sample size was estimated assuming a null pCR proportion of 0.15 and an alternative pCR proportion of 0.30 (α = 0.05, power = 0.80). The proposed treatment could be considered promising if ≥13 pCRs were observed in 55 patients (EudraCT: 2018-004758-39; NCT04083365).

RESULTS

Between November 2019 and August 2021, 60 patients were accrued, of which 55 were assessable for the study's objectives. Two patients experienced disease progression during treatment. Nineteen out of 55 eligible patients achieved a pCR (34.5%, 95% confidence interval 22.2% to 48.6%). Regarding toxicity related to durvalumab, grade 3 adverse events (AEs) occurred in four patients (7.3%) (diarrhea, skin toxicity, transaminase increase, lipase increase, and pancolitis). Grade 4 toxicity was not observed. In 20 patients (36.4%), grade 1-2 AEs related to durvalumab were observed. The most common were endocrine toxicity (hyper/hypothyroidism), dermatologic toxicity (skin rash), and gastrointestinal toxicity (transaminase increase, nausea, diarrhea, constipation).

CONCLUSION

This study met its primary endpoint showing that CRT followed by durvalumab could increase pCR with a safe toxicity profile. This combination is a promising, feasible strategy worthy of further investigation.