Analysis of patients with locally advanced rectal cancer given neoadjuvant radiochemotherapy with or without RT dose intensification: A multicenter retrospective study - ATLANTIS part I

INTRODUCTION

Preoperative radiochemotherapy (RCHT) is the standard of care for locally advanced rectal cancer (LARC). While there are several data regarding chemotherapy intensification, actually, no reliable data directly comparing different radiotherapy (RT) dose levels are available. The present study aimed to compare intensified RT versus standard dose in patients with LARC.

MATERIALS AND METHODS

Data from 12 centers were collected for the current large retrospective study. The primary end-point evaluated whether RT dose intensification was associated with an increased pathological complete response (pCR). The secondary end-points explored the relation between RT dose and interval to surgery, downstaging, and RT-related toxicity. Subgroup analysis according to primary tumor stage was also performed.

RESULTS

1028 patients were analysed. All patients received combined RCHT with (364) or without (664) a RT boost. Patients underwent surgery after a median 10 weeks (IQ range 5-28). The overall pCR rate was 21.5 %. In the boost and no-boost groups, the pCR was 26.6 % (97) and 17 % (114) (p = 0.00), respectively. As a subgroup analysis, the pCR stratified by interval to surgery was 10 %, 23 %, 26.3 %, and 39.3 % (p < 0.000) in the boost group versus 10.6 %, 20.8 %, 19.3 %, and 20.4 % (p = 0.018) in the no-boost group. cT3 patients operated on ≥ week 11 and cT4 patients, regardless of time to surgery, received a significant benefit by the RT boost in terms of pCR rate. Patients in the boost group had a higher rate of grade ≥ 3 acute gastrointestinal toxicities (6 % vs. 1.7 %; p = 0.003).

CONCLUSION

Our results suggest that RT dose intensification (boost) in LARC might significantly increase the pCR rate, although with a small increase in acute toxicity. While pCR seems only partially improved by prolonged time to surgery in the no-boost group, a progressive and significant pCR improvement in patients treated with boost over time was observed. RT boost seems to be beneficial only in more advanced primary tumors.

The Role of Indocyanine Green in Laparoscopic Low Anterior Resections for Rectal Cancer Previously Treated With Chemo-radiotherapy: A Single-center Retrospective Analysis

AIM

Anastomotic leakage represents the most fearful complication in colorectal surgery. Important risk factors for leakage are low anastomoses and preoperative radiotherapy. Many surgeons often unnecessarily perform a protective ileostomy, increasing costs and necessitating a second operation for recanalization. The aim of this study was to evaluate the role of indocyanine green in assessing bowel perfusion, even in cases of a low anastomosis on tissue treated with radiotherapy.

PATIENTS AND METHODS

Two groups of patients were selected: Group A (risky group) with only low extraperitoneal rectal tumors (<8 cm) previously treated with neoadjuvant chemo-radiotherapy; group B (no risk group) with only intraperitoneal rectal tumors (>8 cm), not previously treated with neoadjuvant therapy. Clinical postoperative outcome, morbidity, mortality and anastomotic leakage were compared between these two groups.

RESULTS

In group A, comprised of 35 patients, the overall complication rate was 8.6%, with two patients developing anastomotic leakage (5.7%). In group B, comprised of 53 patients, the overall complication rate was 17% with four cases with anastomotic leakage (7.5%). No statistical difference was observed for conversion rate, general complications, or anastomotic leakage. No statistical differences were observed in clinical variables except for American Society of Anesthesiologist score (p=0.04). Patients who developed complications during radiotherapy had no significant differences in postoperative outcomes compared with other patients.

CONCLUSION

Indocyanine green appears to be safe and effective in assessing the perfusion of colorectal anastomoses, even in the highest-risk cases, potentially reducing the rate of ileostomy. The main limitation remains the lack of a universally replicable standard assessment.

Lymph Node Metastasis in Extraperitoneal Rectal Cancer After Neoadjuvant Therapy: An Unsolved Problem?

BACKGROUND/AIM

Thanks to the promising benefits obtained in terms of quality of life, there has been growing interest in organ-sparing approaches after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer, mainly represented by transanal local excision and watch-and-wait. The main mandatory criterion is complete lymph nodal response (pN0). However, considering the reduced specificity of current radiological means in identifying one-to-one correspondence between clinical and pathological staging, the problem of underestimating lymph nodal involvement remains unsolved. The aim of this study was to identify the true percentage of patients eligible for conservative surgery and possible predictive factors.

PATIENTS AND METHODS

Data for 59 patients with rectal cancer treated with nCRT followed by total mesorectal excision were analyzed. Patients with metastatic tumors and tumors treated with up-front surgery were excluded. Our primary endpoint was the pathological lymph nodal response rate after neoadjuvant chemoradiotherapy. The secondary endpoint was to identify predictive factors for lymph nodal response.

RESULTS

The percentage of patients with pN0 was 62.71%, while in 37.28%, an organ-sparing approach would have not been oncologically correct. Parameters associated with pN0 were lower tumor size (T0-T2) (p=0.013) and lower grading (<G3) (p=0.06). Parameters associated with poorer disease-free survival were pN+ (p=0.019), higher lymph node ratio (p=0.001), and higher stage (p=0.038).

CONCLUSION

Organ-sparing approaches may be a promising option in patients with extraperitoneal rectal cancerthat respond to nCRT. Nevertheless, it is essential to consider the limit of lymph node metastases to ensure oncological safety and, especially in cases with advanced tumors, total mesorectal excision should be the approach of choice.

Comparative analysis of toxicity in patients with anal cancer undergoing definitive simultaneous integrated boost (SIB) or sequential integrated boost (SeqB) radiotherapy

PURPOSE

To compare toxicity of radiotherapy (RT) with concomitant chemotherapy (CHT) in patients (pts) with anal cancer treated with simultaneous integrated boost (SIB) versus sequential boost (SeqB).

METHODS

Sixty-six patients were treated from 2007 to 2021. Thirty patients underwent to SeqB concurrent to CHT and 37 to SIB-group. Toxicity assessment has been considered in acute and in late toxicities for gastrointestinal (GI), genitourinary (GU), cutaneous (CU) districts, according to Common Terminology Criteria for Adverse Events (CTCAE), Version 5.0. The Wexner scale among summary scoring systems has been used as a tool to measure fecal incontinence. The chi-square test for ordinal variables were used to evaluate the association between patient and treatment characteristics and acute or late severe toxicity. Univariable logistic regression models were fit to evaluate predictive factors associated with fecal incontinence.

RESULTS

Median follow-up was 61.5 months (IQR, 27.1-121.7 months) for all patients. Severe acute toxicity (≥ G2) was observed in 49 patients (74.2%). Late toxicity (≥ G2) occurred in 13 cases (19.6%). In assessment of cutaneous toxicity, there was also a significant reduction in ≥ G1 in SIB group with 29 patients (80.5%) vs SeqB group with 29 patients (96.6%) (p-value = 0.046). Of both groups 11 patients (16.6%) developed fecal incontinence, 8 (22%) in the SIB group and 3 (10%) in the SeqB.

CONCLUSION

SIB for anal cancer treatment results in reduced acute and late cutaneous toxicity compared to SeqB. According to our results the rate of other acute and late toxicities are low and comparable between the two groups.

Management of radiation-induced oral mucositis in head and neck cancer patients: a real-life survey among 25 Italian radiation oncology centers

AIM

Radiation-induced oral mucositis (RIOM) is the most frequent side effect in head and neck cancer (HNC) patients treated with curative radiotherapy (RT). A standardized strategy for preventing and treating RIOM has not been defined. Aim of this study was to perform a real-life survey on RIOM management among Italian RT centers.

METHODS

A 40-question survey was administered to 25 radiation oncologists working in 25 different RT centers across Italy.

RESULTS

A total of 1554 HNC patients have been treated in the participating centers in 2021, the majority (median across the centers 91%) with curative intent. Median treatment time was 41 days, with a mean percentage of interruption due to toxicity of 14.5%. Eighty percent of responders provide written oral cavity hygiene recommendations. Regarding RIOM prevention, sodium bicarbonate mouthwashes, oral mucosa barrier agents, and hyaluronic acid-based mouthwashes were the most frequent topic agents used. Regarding RIOM treatment, 14 (56%) centers relied on literature evidence, while internal guidelines were available in 13 centers (44%). Grade (G)1 mucositis is mostly treated with sodium bicarbonate mouthwashes, oral mucosa barrier agents, and steroids, while hyaluronic acid-based agents, local anesthetics, and benzydamine were the most used in mucositis G2/G3. Steroids, painkillers, and anti-inflammatory drugs were the most frequent systemic agents used independently from the RIOM severity.

CONCLUSION

Great variety of strategies exist among Italian centers in RIOM management for HNC patients. Whether different strategies could impact patients' compliance and overall treatment time of the radiation course is still unclear and needs further investigation.

P17.09.A Regorafenib and Re-irradiation: analysis of clinical outcomes and toxicities in patients with recurrent glioblastomas

Background

Glioblastoma is the most common and aggressive primary brain tumor in adults.The aggressiveness and poor prognosis related to this disease join to the limited available treatment options. The current standard of care involves surgical resection followed by concomitant radiotherapy and chemotherapy. At recurrence, no standard treatment exists and there are no guidelines to facilitate decisions in the recurrent setting. Available options include re-operation, re-irradiation, systemic therapy, alone or in combination. In recent years, immunotherapy strategies have revolutionized the treatment of many cancers, increasing the hope for GBM therapy. Regorafenib (Stivarga) is an inhibitor of several kinases involved in the mechanisms that regulate neoangiogenesis processes, through the inhibition vascular endothelial growth factor (VEGF) receptors and the modifications of the tumor microenvironment; specifically, Regorafenib binds and stabilizes PSAT1 (phosphoserine aminotransferase 1). The dual regulatory mechanism underlying PSAT1-induced autophagy arrest accounts for the superior anti-GBM effect of Regorafenib compared with Temozolomide.

Material and Methods

15 patients with documented disease progression after surgery followed by RT and TMZ were assigned to receive regorafenib (REG) 160 mg once daily for the first 3 weeks of each 4-week cycle. All patients received prior radiation therapy (RT) to a median dose of 60 Gy (range 40.05 -60). Median time to retreatment after prior RT was 16 months (range 14-33). Tumor volumes ranged from 81.7 cm3 to 422.4 cm3 (CTV) and from 112.7 cm3 to 422.4 cm3 (PTV).3 patients (20%) received concomitant reirradiation with a radiation dose of 37.5 Gy in 15 fractions of 2.5 Gy.

Results

the median follow-up was 9.5 months (range 5-22). The overall survival and the progression-free survival rates were 53,8 %, and 46,6 % respectively at 2 years. In 53% the symptoms were stable. Only one patient developed late toxicity: acute pancreatitis (Grade I) regressed on interruption of Regorafenib. No other neurological deficits occurred during follow-up. At last follow up 60% of patients were alive.

Conclusion

we report our experience with Regorafenib, administered in patients with rapid progression after the end of postoperative radio chemotherapy treatment. Regorafenib might be a new potential treatment option for recurrent glioblastoma: it was well tolerated also in cases of combined treatment with reirradiation and appeared effective. Other studies will be necessary to evaluate and confirm the role of Regorafenib in glioblastoma patients and the potential effectiveness of the combined therapeutic strategy: Regorafenib-reirradiation.