Preoperative chemotherapy and radiotherapy for locally advanced rectal cancer

Surgical margins in head and neck squamous cell carcinoma: A narrative review

Head and neck squamous cell carcinoma (HNSCC), a prevalent and frequently recurring malignancy, often necessitates surgical intervention. The surgical margin (SM) plays a pivotal role in determining the postoperative treatment strategy and prognostic evaluation of HNSCC. Nonetheless, the process of clinical appraisal and assessment of the SMs remains a complex and indeterminate endeavor, thereby leading to potential difficulties for surgeons in defining the extent of resection. In this regard, we undertake a comprehensive review of the suggested surgical distance in varying circumstances, diverse methods of margin evaluation, and the delicate balance that must be maintained between tissue resection and preservation in head and neck surgical procedures. This review is intended to provide surgeons with pragmatic guidance in selecting the most suitable resection techniques, and in improving patients' quality of life by achieving optimal functional and aesthetic restoration.

Prospective evaluation of dose-escalated preoperative concurrent chemo-radiation with image guided-IMRT in locally advanced rectal cancers

Purpose

To analyse the safety and efficacy of neoadjuvant chemoradiation (NACRT) with dose-escalated image-guided intensity modulated radiation therapy (IG-IMRT) in locally advanced (T3/4; T1-4N1-2) rectal cancers (LARCs).

Materials and methods

Twenty patients with the diagnosis of LARC were recruited in this prospective interventional single-arm study treated by IG-IMRT with 45 Gray (Gy) in 25 fractions to elective nodal volumes and 55 Gy in 25 fractions to the gross primary and nodal disease with concurrent capecitabine 825 mg/m2 twice daily on radiotherapy days. Patients underwent total mesorectal excision 6-8 weeks post completion of NACRT followed by adjuvant chemotherapy (Capecitabine and oxaliplatin every 3 weekly for 6-8 cycles). Primary end point was acute toxicity assessment and secondary end points were pathological complete response (pCR) and loco-regional control (LRC).

Results

Clinical T stage was T3:T4 in 19:1 and clinical N0:N1: N2 in 2:7:11 patients, respectively. With a median follow up of 21.2 months (13.8-25.6 months), 18 of 20 (90%) patients received the full course of treatment. Tumour and nodal downstaging was achieved in 78% and 84% of patients, respectively. pCR and overall complete response (defined as pCR and near CR) was achieved in 22.2% and 44.4% of patients, respectively. 2 (10%) patients completed NACRT, and achieved complete clinical response but refused surgery. Adjuvant chemotherapy course was completed by 17/18 (94.5%) patients. Grade 3 toxicities were observed in 2 (10%) patients during NACRT. All patients were disease-free at the time of the last follow up.

Conclusion

Dose-escalation of NACRT therapy with IG-IMRT in LARC patients offers decent rates of pCR and overall response with excellent LRC and acceptable toxicities.

Neoadjuvant radiotherapy dose escalation for locally advanced rectal cancers in the new era of radiotherapy: A review of literature

BACKGROUND

The standard treatment of locally advanced rectal cancers (LARC) consists on neoadjuvant chemoradiotherapy followed by total mesorectal excision. Different data in literature showed a benefit on tumor downstaging and pathological complete response (pCR) rate using radiotherapy dose escalation, however there is shortage of studies regarding dose escalation using the innovative techniques for LARC (T3-4 or N1-2).

AIM

To analyze the role of neoadjuvant radiotherapy dose escalation for LARC using innovative radiotherapy techniques.

METHODS

In December 2020, we conducted a comprehensive literature search of the following electronic databases: PubMed, Web of Science, Scopus and Cochrane library. The limit period of research included articles published from January 2009 to December 2020. Screening by title and abstract was carried out to identify only studies using radiation doses equivalent dose 2 Gy fraction (EQD2) ≥ 54 Gy and Volumetric Modulated Arc Therapy (VMAT), intensity-modulated radiotherapy or image-guided radiotherapy (IGRT) techniques. The authors’ searches generated a total of 2287 results and, according to PRISMA Group (2009) screening process, 21 publications fulfil selection criteria and were included for the review.

RESULTS

The main radiotherapy technique used consisted in VMAT and IGRT modality. The mainly dose prescription was 55 Gy to high risk volume and 45 Gy as prophylactic volume in 25 fractions given with simultaneous integrated boosts technique (42.85%). The mean pCR was 28.2% with no correlation between dose prescribed and response rates (P value ≥ 0.5). The R0 margins and sphincter preservation rates were 98.88% and 76.03%, respectively. After a mean follow-up of 35 months local control was 92.29%. G3 or higher toxicity was 11.06% with no correlation between dose prescription and toxicities. Patients receiving EQD2 dose > 58.9 Gy and BED > 70.7 Gy had higher surgical complications rates compared to other group (P value = 0.047).

CONCLUSION

Dose escalation neoadjuvant radiotherapy using innovative techniques is safe for LARC achieving higher rates of pCR. EQD2 doses > 58.9 Gy is associated with higher rate of surgical complications.

Neoadjuvant Radiotherapy Dose Escalation in Locally Advanced Rectal Cancer: a Systematic Review and Meta-analysis of Modern Treatment Approaches and Outcomes

AIMS

Improving pathological complete response (pCR) rates after neoadjuvant chemoradiotherapy for locally advanced rectal cancer may facilitate surgery-sparing treatment paradigms. Radiotherapy boost has been linked to higher rates of pCR; however, outcomes in moderately escalated inverse-planning studies have not been systematically evaluated. We therefore carried out a systematic review and meta-analysis of radiation dose-escalation studies in the context of neoadjuvant therapy for locally advanced rectal cancer.

MATERIALS AND METHODS

A systematic search of Pubmed, EMBASE and Cochrane databases for synonyms of 'rectal cancer', 'radiotherapy' and 'boost' was carried out. Studies were screened for radiotherapy prescription >54 Gy. Prespecified quality assessment was carried out for meta-analysis inclusion suitability. Pooled estimates of pCR, acute toxicity (grade ≥3) and R0 resection rates were determined with random-effects restricted maximum-likelihood estimation. Heterogeneity was assessed with Higgins I² and Cochran Q statistic. Subset analysis examined outcomes in modern inverse-planning studies. Meta-regression with permutation correction was carried out for each outcome against radiation dose, radiotherapy technique, boost technique, chemotherapy intensification and other patient- and treatment-related cofactors.

RESULTS

Forty-nine primary and three follow-up publications were included in the systematic review. Pooled estimates of pCR, toxicity and R0 resection across 37 eligible publications (n = 1817 patients) were 24.1% (95% confidence interval 21.2-27.4%), 11.2% (95% confidence interval 7.2-17.0%) and 90.7% (95% confidence interval 87.9-93.8%). Within inverse-planning studies (17 publications, n = 959 patients), these rates were 25.7% (95% confidence interval 21.0-31.1%), 9.8% (95% confidence interval 4.6-19.7%) and 95.3% (95% confidence interval 91.6-97.4%). Regression analysis did not identify any significant predictor of pCR (P > 0.05).

CONCLUSIONS

Radiotherapy dose escalation above 54 Gy is associated with high rates of pCR and does not seem to increase the risk of acute grade ≥3 toxicity events. pCR rates approaching 25% may be achievable utilising moderate escalation (54-60 Gy) with modern inverse-planning techniques; however, a clear dose-response relationship was not identified in regression analysis and additional evidence is awaited given the prevalence of heterogenous single-arm studies to date.

Anemia response and safety to epoetin-beta treatment in patients with neoadjuvant therapy prior to primary digestive tract tumor surgery

PURPOSE

Anemia is common during anticancer treatment. This study aimed to evaluate the response and safety of treatment with epoetin-beta (EB) in patients with neoadjuvant therapy prior to primary digestive tract tumor surgery.

PATIENTS AND METHODS

In this open-label, single-arm study, patients (n = 22) with hemoglobin (Hb) levels below 11 g/dl who received epoetin-beta 450 IU/kg (30,000 IU) weekly until the hemoglobin level reached 12 g/dl.

RESULTS

After treatment with EB, a mean absolute increment of 2.6 g/dl was attained. The mean hemoglobin values during the study were pretreatment 10.1 g/dl, half-way through treatment 12.3 g/dl, 4 weeks after concomitant radiochemotherapy 12.7 g/dl, the week prior to surgery 12.5 g/dl, and after surgery 10.9 g/dl. No patient required transfusion before or after surgery. The probability or risk of postoperative complications was 27.3%, and included one rectovaginal fistula, one parastomal hernia, one case of ileus and two surgical wound infections. In this series, downstaging was observed in 81.8% of patients, and downsizing in 90.9%. Most interestingly, histopathological complete response rate was achieved by 18.2%.

CONCLUSIONS

Epoetin-beta (EB) treatment in our series of patients with digestive malignancies subjected to neoadjuvant radiochemotherapy proved effective and safe, avoiding the need for transfusion during surgery.

Local recurrence after laparoscopic resection of T3 rectal cancer without preoperative chemoradiation and a risk group analysis: an Asian collaborative study

Risk factors for local recurrence and indication for preoperative radiation therapy have not been well evaluated for patients undergoing laparoscopic rectal cancer operation. From 1998 to 2004, 497 T3 rectal cancer patients with tumor located within 12 cm from the anal verge who had undergone laparoscopic surgery without preoperative radiation therapy by eight experienced laparoscopic surgeons in four Asian countries were reviewed retrospectively for the incidence of local recurrence and related factors. The median follow-up was 29.0 months (range, 6.0 to 92.3), and 31 cases of local recurrence were observed during the follow-up period (6 anastomosis site, 6 perineum, 17 pelvic wall, and 2 unclassified). The estimated local recurrence rates at 24 and 60 months were 5.42 and 9.41%, respectively. Patient's gender, tumor location, lymph node metastasis, and tumor perforation were independent factors for local recurrence by multivariate analysis. The local recurrence rate was comparable to previous studies using conventional open surgery with preoperative chemoradiation, except for a subgroup of male patients with the tumor located within 7 cm from the anal verge. The indication for preoperative radiation therapy would be different from those who will undergo conventional open surgery, and further evaluation of the benefits of preoperative radiation therapy is required for those with low risk tumor.

Tumor response to neoadjuvant chemoradiation in rectal cancer: predictor for surgical morbidity?

BACKGROUND

Increasing the rate of pathological complete remissions after neoadjuvant chemoradiation of rectal cancer has become a strategy to further improve the long-term oncological outcome of patients. This report evaluates the influence of preoperative intensified radiochemotherapy on the rate and outcome of surgical complications.

MATERIALS AND METHODS

Patients with primary rectal cancer at stages cT3/4cNx or N+ without metastasis were preoperatively treated either with capecitabine and irinotecan or with capecitabine, irinotecan and ceutximab with a concurrent radiation (50.4 Gy). Surgery was scheduled 4-7 weeks after completion of the chemoradiation. Perioperative complications were prospectively documented during the patient's hospital stay.

RESULTS

Fifty-nine patients (median age 60; male/female: 46/13) undergoing surgery at a single center were analysed. The median distance of the tumour from the dentate line was 5 cm. The operations performed were low anterior resection (n=45), Hartmann's procedure (n=4) and abdominoperineal resection (n=10). Total mesorectal excision with R0-resection was accomplished in all but one patients. Histopathological regression was described in four grades (0-3) as defined by the Japanese Society for Cancer of the Colon and Rectum. Tumors were called major responsive when assigned to the regression grades 3 or 2, and minor or nonresponsive at regression grades 1 or 0. In total, 33 patients (55.9%) had a regression grade 2 or 3. Among them, 12 patients showed a pathological complete response without any residual cancer cell (20.3%). Seven out of 45 patients (15.5%) with sphincter-preserving surgery suffered from suture breakdown; they all had previously shown a major response of the resected tumor. Two of them died during the hospital stay.

CONCLUSIONS

While in general, patients undergoing neoadjuvant intensified treatment suffer from a slight increase in surgical complications, this is markedly enhanced in patients with good treatment responses. Our results underline the oncological benefit of intensified neoadjuvant chemoradiation, but the severity of complications in low rectal anastomosis of patients with good response after neoadjuvant therapy should alert surgeons and oncologists.

Poloxamer 188 and propylene glycol-based rectal suppository enhances anticancer effect of 5-fluorouracil in mice

The tumoricidal and apoptosis-inducing activities of 5-fluorouracil (5-FU) have been demonstrated in experimental and clinical investigations. Clinically, the 5-FU suppository form has been widely adopted for its advantages of less systemic toxicity, higher local tissue concentrations, and reduced first-pass effect. In this study, we investigated the feasibility of rectal administration of 5-FU suppository based on poloxamer 188 (P188) and propylene glycol (PG) and its anticancer effect on the murine experimental cancer models. The rectal suppository was made with 70% P188 and 30% PG, which was a solid phase at room temperature and instantly melted at physiological temperature. The treatment with the 5-FU suppository was more effective than the oral route in decreasing the volume of rectal cancer in mice. In addition, the survival rate of the mice with rectal cancer was higher in the group treated with the 5-FU suppository than in the group treated with 5-FU orally. Furthermore, in mice skin cancers induced by inoculation of murine CT-26 colon carcinoma cells, the anticancer effect of 5-FU was significantly enhanced by the rectal administration of the suppository than by oral treatment. Taken together, the results suggest that a poloxamer gel system with 5-FU/P188/PG is an effective rectal dosage form for the treatment of both rectal and non-rectal cancers.