A review of preoperative chemoradiotherapy for lower rectal cancer

"WATCH AND WAIT" STRATEGY IN RECTAL CANCER PATIENTS WITH A COMPLETE CLINICAL RESPONSE AFTER NEOADJUVANT CHEMORADIATION THERAPY: A SINGLE-CENTER EXPERIENCE

BACKGROUND

The non-operative management of rectal adenocarcinoma (RA) after neoadjuvant chemoradiation therapy (nCRT) has gained increasing attention. The "Watch and Wait" ("W&W") strategy allows one to avoid surgery-related reduction in the quality of life due to permanent pelvic organ dysfunction or irreversible stoma. Still, the oncological safety of this strategy is under evaluation.

AIM

To share a single-center experience of the "W&W" strategy.

MATERIALS AND METHODS

The retrospective analysis of 125 patients who received nCRT in 2016-2021 was performed. Patients who met the European Society for Medical Oncology (ESMO, 2017) criteria of clinical complete response (cCR) and received non-operative management were analyzed.

RESULTS

Ten patients (8%) were re-staged after nCRT as cCR and followed the "W&W" strategy. Patients' characteristics: 7 female, 3 male; mean age 67.3 years. Tumor characteristics: pre-treatment N+ was present in 7 cases; G1 adenocarcinoma in a majority of cases; mean tumor distance from the anal verge - 5.85 cm; mean tumor circumference - 71%; mean tumor length - 3.87 cm. The mean follow-up time was 30 months. Local regrowth or/and distant metastases developed in 3 cases. The 2-year disease-free survival was 70%.

CONCLUSIONS

Most of the patients following the "W&W" strategy have benefited. However, to reduce the number of relapses, it is necessary to perform a more careful selection of patients.

7-Dehydrocholesterol Encapsulated Polymeric Nanoparticles As a Radiation-Responsive Sensitizer for Enhancing Radiation Therapy

Therapeutics that can be activated by radiation in situ to enhance the efficacy of radiotherapy are highly desirable. Herein, 7-Dehydrocholesterol (7-DHC), a biosynthetic precursor of cholesterol, as a radiosensitizer, exploiting its ability to propagate the free radical chain reaction is explored. The studies show that 7-DHC can react with radiation-induced reactive oxygen species and in turn promote lipid peroxidation, double-strand breaks, and mitochondrial damage in cancer cells. For efficient delivery, 7-DHC is encapsulated into poly(lactic-co-glycolic acid) nanoparticles, forming 7-DHC@PLGA NPs. When tested in CT26 tumor bearing mice, 7-DHC@PLGA NPs significantly enhanced the efficacy of radiotherapy, causing complete tumor eradication in 30% of the treated animals. After treatment, 7-DHC is converted to cholesterol, causing no detectable side effects or hypercalcemia. 7-DHC@PLGA NPs represent a radiation-responsive sensitizer with great potential in clinical translation.

Women are predisposed to early dose-limiting toxicities during adjuvant CAPOX for colorectal cancer

AIM

Oxaliplatin-based adjuvant chemotherapy was demonstrated to be beneficial for stage III or high-risk stage II colorectal cancer (CRC). Moreover, a recent international collaborative trial suggested 3-months CAPOX as an alternative regimen for low-risk stage III colorectal cancer (CRC) patients. Thus, it is important to clarify the frequency and predictive markers of dose-limiting toxicities (DLTs) developed within the short-course CAPOX cycles.

METHODS

We investigated CRC patients who underwent radical surgery and adjuvant CAPOX therapy at our hospital between December 2010 and February 2021. Patients who received initially reduced doses of CAPOX and those who had early recurrence were excluded. We reviewed the age, sex, comorbidities, physical, laboratory and oncological data and other perioperative factors. The associations between these variables and early DLTs within four cycles of CAPOX were examined by multivariate analyses using logistic regression models.

RESULTS

Among 168 patients (96 men, mean age: 58.3 years), 120 (71%) developed early DLTs. Patients with early DLTs were predominantly women and sarcopenic and habitual alcohol consumers. On multivariate analyses, only the female sex was an independent predictive factor for early DLTs (odds ratio: 2.61, P = .027).

CONCLUSION

Women were prone to early DLTs during adjuvant CAPOX in the current study. Doctors should be aware of the sex difference in the incidence of early DLTs, adjust the CAPOX dosage and provide supportive care for female CRC patients.

Evaluation and Predictive Factors of Complete Response in Rectal Cancer after Neoadjuvant Chemoradiation Therapy

The response to neoadjuvant chemoradiation therapy is an important prognostic factor for locally advanced rectal cancer. Although the majority of the patients after neoadjuvant therapy are referred to following surgery, the clinical data show that complete clinical or pathological response is found in a significant proportion of the patients. Diagnostic accuracy of confirming the complete response has a crucial role in further management of a rectal cancer patient. As the rate of clinical complete response, unfortunately, is not always consistent with pathological complete response, accurate diagnostic parameters and predictive markers of tumor response may help to guide more personalized treatment strategies and identify potential candidates for nonoperative management more safely. The management of complete response demands interdisciplinary collaboration including oncologists, radiotherapists, radiologists, pathologists, endoscopists and surgeons, because the absence of a multidisciplinary approach may compromise the oncological outcome. Prediction and improvement of rectal cancer response to neoadjuvant therapy is still an active and challenging field of further research. This literature review is summarizing the main, currently known clinical information about the complete response that could be useful in case if encountering such condition in rectal cancer patients after neoadjuvant chemoradiation therapy, using as a source PubMed publications from 2010–2021 matching the search terms “rectal cancer”, “neoadjuvant therapy” and “response”.

Impact of Fluoropyrimidine and Oxaliplatin-based Chemoradiotherapy in Patients With Locally Advanced Rectal Cancer

BACKGROUND/AIM

To evaluate the benefits of the addition of oxaliplatin (OX) to fluoropyrimidine (FP)-based neoadjuvant chemoradiotherapy (CRT) for patients with locally advanced rectal cancers (LARCs).

PATIENTS AND METHODS

We performed retrospective analyses comparing the pathological complete response (pCR) rate, overall survival (OS), recurrence-free survival (RFS), and local recurrence-free survival (LRFS) between FP-based and FP+OX-based CRT groups and for patients who had completed the CRT.

RESULTS

One hundred patients were included in the analyses: the pCR rate, OS, RFS, and LRFS were similar between these groups. The FP+OX group showed significantly more frequent incompleteness of the CRT compared to the FP group (p=0.049). Among the patients who had completed the CRT, the FP+OX group demonstrated significantly improved LRFS compared to the FP group (p=0.048).

CONCLUSION

The addition of OX to an FP regimen in neoadjuvant CRT for LARC may reduce local recurrence in patients who have achieved good compliance to CRT.