The treatment of locally advanced colon cancer

Assessing the Effect of Radiotherapy in Addition to Surgery in Colon Adenocarcinomas: a Systematic Review and Meta-analysis of Contemporary Evidence

PURPOSE

This study aims to review the contemporary evidence investigating radiotherapy (RT) in addition to surgery for colon adenocarcinomas.

METHODS

We searched the following databases: PubMed, Science Direct, Scopus, ASCOpubs, the Cochrane Library, and Google Scholar. Studies (since January 2005) comparing outcomes of high-risk colon adenocarcinomas who underwent RT in addition to surgery versus no RT were eligible. Pooling of outcomes from published results or from analysis of survival curves was done. Subgroup analysis was conducted to determine if the efficacy of RT varies with RT timing.

RESULTS

Eight studies were included (five retrospective cohorts, three population-based studies). Pooled analysis from retrospective cohorts showed a reduction in 5-year LR (OR 0.41; 95% CI 0.21-0.79; p = 0.007) in the RT group. A benefit in 3-year (OR 1.81; 95% CI 1.15-2.87; p = 0.01) and 5-year (OR 2.10; 95% CI 1.21-3.63; p = 0.008) DFS and in 3-year (OR 2.55; 95% CI 1.43-4.54; p = 0.001) and 5-year (OR 2.00; 95% CI 1.17-3.41; p = 0.01) OS was seen in the RT group. The OS benefit was demonstrated in the subgroup analysis of neoadjuvant RT, but not with adjuvant RT. The improvement in OS with neoadjuvant RT was supported by a population-based study from NCDB, while results from two population-based studies investigating adjuvant RT were conflicting.

CONCLUSION

Taking into account the limitations of the studies, our review of evidence suggests a possible role of RT in improving oncologic outcomes of select colon adenocarcinomas. Prospective studies are needed to definitively assess the value of RT for colon cancer.

Low-kilovolt x-ray intraoperative radiotherapy for pT3 locally advanced colon cancer: a single-institution retrospective analysis

Background

Patients with locally advanced colon cancer (LACC) treated with surgery had a high risk of local recurrence. The outcomes can vary significantly among patients with pT3 disease. This study was undertaken to assess whether low-kilovolt (kV) x-ray intraoperative radiotherapy (IORT) can achieve promising results compared with electron beam IORT (IOERT) and whether specific subgroups of patients with pT3 colon cancer may benefit from low-kV x-ray IORT.

Methods

We retrospectively reviewed 44 patients with pT3 LACC treated with low-kV x-ray IORT. Clinicopathologic characteristics were analyzed to identify patients that could potentially benefit from low-kV x-ray IORT. The Kaplan-Meier survival analysis was used to assess overall survival (OS) and progression-free survival (PFS). Correlation analysis was used to discover the association of multiple factors to the results of treatment represented by the values of OS and PFS.

Results

The median follow-up of patients was 20.5 months (range, 6.1–38.8 months). At the time of analysis, 38 (86%) were alive and 6 (14%) had died of their disease. The 3-year Kaplan-Meier of PFS and OS for the entire cohort was 82.8% and 82.1%, respectively. At median follow-up, no in-field failure within the low-kV x-ray IORT field had occurred. Locoregional and distant failure had occurred in 2 (5%) patients each. The rate of perioperative 30-day mortality was 0%, and the morbidity rate was 11%. Five patients experienced 7 complications, including 4 early complications (30 days) and three late complications (> 30 days) leading early and late morbidity rates of 9% and 7%, respectively.

Conclusion

Patients with LACC who had undergone an additional low-kV x-ray IORT can achieve encouraging locoregional control, PFS, OS, and distant control without an increase in short-term or long-term complications. Low-kV x-ray IORT can be considered as part of management in pT3 LACC.

Intraoperative radiotherapy as an immediate adjuvant treatment of rectal cancer due to limited access to external-beam radiotherapy

BACKGROUND

Neoadjuvant external-beam radiotherapy (EBRT) with concomitant chemotherapy is the current standard-of-care for locally-advanced rectal cancer. Intraoperative radiotherapy (IORT) is to date only recommended for pelvic recurrences or incompletely resectable tumors. We here report on patients with stage II/III rectal cancer that were treated with IORT in a regional Russian university center due to limited access to EBRT.

METHODS

We retrospectively analyzed data from patients that were diagnosed with locally-advanced rectal cancer and underwent surgery from December 2012 to October 2016 at a regional oncological center in Russia (Krasnodar). During this period, access to EBRT was limited due to a temporary lack of a sufficient number of EBRT facilities. Patients unable to travel to a distant radiotherapy site received IORT alone, those that could travel received neoadjuvant external beam (chemo-) radiotherapy. Factors of interest were tumor stage, tumor differentiation, resection status, surgery type and neoadjuvant or adjuvant chemotherapy. We assessed local progression-free survival (L-PFS), PFS and overall survival (OS).

RESULTS

A total of 172 patients were included in this analysis. Of those, 92 (53.5%) were treated with IORT alone (median dose: 15 Gy [8.4-17 Gy]) and 80 (46.5%) received both neoadjuvant EBRT (median dose: 50.4 Gy [40-50.4 Gy]) and IORT (median dose: 15 Gy [15-17 Gy]). The median age was 65 years [33-82]. The median follow-up was 23 months [0-63 months]. The incidence of toxicity was low in both groups with an overall complication rate of 5.4%. Local PFS at 4 years was comparable with 59.4% in the IORT group and 65.4% in the IORT/EBRT group (p = 0.70). Similarly, there was no difference in OS or PFS (p = 0.66, p = 0.51, respectively).

CONCLUSIONS

IORT is a valuable option for patients with locally-advanced rectal cancer in the absence of access to EBRT.

Adjuvant radiation therapy for T4 non-rectal colon adenocarcinoma provides a cause-specific survival advantage: A SEER database analysis

PURPOSE

While there is no level 1 evidence supporting the use of adjuvant radiotherapy (RT) for non-rectal colon cancer in the modern chemotherapy era, there are studies that suggest a local control benefit. This treatment modality is not part of standard treatment recommendations, and we hypothesized that adjuvant RT provides a benefit in locally advanced disease. Due to the limited number who receive post-operative RT, a national database was searched to provide sufficient power.

MATERIALS AND METHODS

A retrospective analysis using the Surveillance, Epidemiology, and End Results (SEER) database was performed. Inclusion criteria were: non-rectal colon cancer, AJCC 6th or 7th edition T4 and M0, oncologic resection, and 1st cancer site. Patients were excluded for RT prior to or during surgery, or if the sequence of RT was unknown. Using a Cox proportional hazard model, the relative risk of cause-specific mortality for "RT after surgery" versus "No RT" was calculated.

RESULTS

21,789 patients were identified who met the inclusion criteria. Of these, only 1001 received adjuvant RT, and 64% were node-positive (53% RT vs. 65% no RT). When comparing RT vs. no RT, after adjusting for sex, age, N stage, and grade, we determined the relative risk of death from cancer was 0.8849 (95% CI: 0.8008-0.9779; p = 0.0165), suggesting that only 14 patients with T4 disease need receive adjuvant radiation to spare a cancer-related death.

CONCLUSIONS

Adjuvant RT is not routinely utilized for definitive treatment of T4 non-rectal colon cancer, but this analysis shows a significant cause-specific survival benefit.

Intraoperative radiation therapy for colon and rectal cancers: a clinical review

Although there have been significant advances in the adjuvant therapy of colorectal cancer, results for patients have historically been poor when complete resection is unlikely or not possible. Similarly, locally recurrent colorectal cancer patients often experience significant tumor related morbidity and disease control and long term survival have historically been poor with standard therapies. Intraoperative radiation therapy (IORT) has been proposed as a possible tool for dose escalation in patients with locally advanced colorectal cancer.

For patients with locally advanced primary or recurrent colon cancer, the absence of prospective controlled trials limits the ability to draw definitive conclusions in completely resected patients. In subtotally resected patients, the available evidence is consistent with marked improvements in disease control and survival compared to historical controls. For patients with locally advanced primary or recurrent rectal cancer, a relatively large body of evidence suggests improved disease control and survival, especially in subtotally resected patients, with the addition of IORT to moderate dose external beam radiation (EBRT) and chemotherapy. The most important prognostic factor in nearly all series is the completeness of surgical resection. Many previously irradiated patients may be carefully re-treated with radiation and IORT in addition to chemotherapy resulting in long term survival in more than 25% of patients. Peripheral nerve is dose limiting for IORT and patients receiving 15 Gy or more are at higher risk.

IORT is a useful tool when dose escalation beyond EBRT tolerance limits is required for acceptable local control in patients with locally advanced primary or recurrent colorectal cancer. Previously irradiated patients should not be excluded from treatment consideration.

Results of intraoperative electron beam radiotherapy containing multimodality treatment for locally unresectable T4 rectal cancer: a pooled analysis of the Mayo Clinic Rochester and Catharina Hospital Eindhoven

BACKGROUND

The aim of this study is to analyse the pooled results of intraoperative electron beam radiotherapy (IOERT) containing multimodality treatment of locally advanced T4 rectal cancer, initially unresectable for cure, from the Mayo Clinic, Rochester, USA (MCR) and Catharina Hospital, Eindhoven, The Netherlands (CHE), both major referral centers for locally advanced rectal cancer. A rectal tumor is called locally unresectable for cure if after full clinical work-up infiltration into the surrounding structures or organs has been demonstrated, which would result in positive surgical margins if resection was the initial component of treatment. This was the reason to refer these patients to the IOERT program of one of the centers.

METHODS

In the period from 1981 to 2010, 417 patients with locally unresectable T4 rectal carcinomas at initial presentation were treated with multimodality treatment including IOERT at either one of the two centres. The preferred treatment approach was preoperative (chemo) radiation and intended radical surgery combined with IOERT. Risk factors for local recurrence (LR), cancer specific survival, disease free survival and distant metastases (DM) were assessed.

RESULTS

A total of 306 patients (73%) underwent a R0 resection. LRs and metastases occurred more frequently after an R1-2 resection (P<0.001 and P<0.001 respectively). Preoperative chemoradiation (preop CRT) was associated with a higher probability of having a R0 resection. Waiting time after preoperative treatment was inversely related with the chance of developing a LR, especially after R+ resection. In 16% of all cases a LR developed. Five-year disease free survival and overall survival (OS) were 55% and 56% respectively.

CONCLUSIONS

An acceptable survival can be achieved in treatment of patients with initially unresectable T4 rectal cancer with combined modality therapy that includes preop CRT and IOERT. Completeness of the resection is the most important predictive and prognostic factor in the treatment of T4 rectal cancer for all outcome parameters. IOERT can reduce the LR rate effectively, especially in R+ resected patients.

Integration of radiation oncology with surgery as combined-modality treatment

Integration of surgery and radiation (external beam, EBRT; intraoperative, IORT) has become more routine for patients with locally advanced primary cancers and those with local-regional relapse. This article discusses patient selection and treatment from a more general perspective, followed by a discussion of patient selection and treatment factors in select disease sites (pancreas cancer, colorectal cancer, retroperitoneal soft-tissue sarcomas). Outcomes with combined modality treatment (surgery, EBRT alone or with concurrent chemotherapy, IORT) are discussed. The ultimate in contemporary integration of radiation and surgery is found in patients who are candidates for surgery plus both EBRT and IORT.

Can unresectable colorectal cancer be cured?

A multimodality regimen that includes EBRT, chemotherapy, maximal surgical resection, and IORT, when used in patients with initially unresectable primary colon or rectal adenocarcinoma, is associated with excellent long-term local control, and a 5-year overall survival of 52%. Distant metastases account for most treatment failures, occurring in roughly 50%. Treatment-related morbidity is high, with a long-term complication rate that approaches 50%. These results suggest that selected patients with advanced unresectable disease benefit from an aggressive approach. Additional effort needs to focus on reducing the rate of systemic failure with more effective chemotherapy regimens and minimizing the frequency of long-term procedural complications.

Unresectable colorectal cancer can be cured with multimodality therapy

OBJECTIVE

The aim of this study was to determine in what manner aggressive external beam radiotherapy (EBRT), chemotherapy, surgical resection, and intraoperative radiotherapy (IORT) impact relapse and survival in patients with locally unresectable primary colorectal cancer.

SUMMARY BACKGROUND DATA

Patients with colorectal cancer fixed to critical structures (eg, IVC and pelvic sidewall) are considered locally "unresectable" for cure and treated with palliative therapy.

METHODS

One hundred forty-six patients (65% males) with locally unresectable colon (40) and rectal (106) cancer were treated with EBRT, chemotherapy, surgical resection, and IORT. Final surgical margins were close, but negative in 100 patients (68%), microscopically positive in 28 (19%), and grossly positive in 18 (13%). Kaplan-Meier method was used to visualize survival and relapse curves; groups were compared using the log-rank test.

RESULTS

Median overall survival was 3.7 years. Median overall survival (years) favored patients with age <58 (7.6 vs. 3.6; P = 0.0012), those receiving adjuvant chemotherapy (9.4 versus 3.9; P = 0.0019), and those with negative or microscopic margins (6.3 vs. 1.9; P = 0.0006). There were no perioperative deaths. Fifteen complications occurred in 12 patients (8%) within 30 days of surgery/IORT. One hundred nineteen long-term complications occurred in 77 patients (53%), most commonly peripheral neuropathy (19%), bowel obstruction (14%), and ureteral obstruction (12%).

CONCLUSIONS

Aggressive multimodality therapy for locally unresectable primary colorectal cancer results in excellent local disease control and a 5-year disease-free and overall survival rate of 43% and 52% respectively with no operative mortality and acceptable perioperative morbidities.

Radiation therapy for gastrointestinal cancer

This article has reviewed the current role of radiation in the treatment of gastrointestinal malignancies and discussed the data supporting its use. Radiation treatment in this setting continues to evolve with the increasing implementation of more conformal delivery techniques. Further scientific investigation is needed to establish the optimal role of radiation and to better define its integration with novel systemic and biologic modalities.

Colon cancer

Colon cancer is one of the leading tumours in the world and is considered among the big killers, together with lung, prostate and breast cancer. In the recent years very important advances occurred in the field of treatment of this frequent disease: adjuvant chemotherapy was demonstrated to be effective, chiefly in stage III patients, and surgery was optimized in order to achieve the best results with a low morbidity. Several new target-oriented drugs are under evaluation and some of them (cetuximab and bevacizumab) have already exhibited a good activity/efficacy, mainly in combination with chemotherapy. The development of updated recommendations for the best management of these patients is crucial in order to obtain the best results, not only in clinical research but also in everyday practice. This report summarizes the most important achievements in this field and provides the readers useful suggestions for their professional practice.

Intraoperative radiotherapy in the multimodality approach to colorectal cancer

The addition of intraoperative radiotherapy (IORT) to the multimodality approach for the treatment of locally advanced and locally recurrent colorectal cancer seems to result in improvements in local control and long-term survival. Local control and survival are most likely in patients in whom a gross total resection is accomplished. Peripheral nerve is the dose-limiting structure for patients treated with IORT. Further improvements in local control require the addition of dose modifiers during external beam radiotherapy or IORT. Distant relapse remains problematic, and effective systemic therapy is necessary to significantly improve long-term survival.

[Chemoradiotherapy in the adjuvant treatment of gastric adenocarcinomas: real progress?]

Frequency of local and distant failures after gastrectomy has led to extended lymph nodes dissection to obtain a better locoregional control. However, five year survival rates were not significantly different between patients undergoing D2 and D1 lymphadenectomy, and higher morbidity and post operative deaths were reported in large randomised trials (respectively 25% vs 48% and 4 vs 13%). Additionally, several metanalysis failed to demonstrate a significant survival advantage with adjuvant chemotherapy. The results of the first trial demonstrating one advantage to adjuvant post-operative chemoradiotherapy should modify the standard care. Disease free and overall survival after surgery alone and after surgery and concurrent chemoradiotherapy were respectively 31% vs 48% and 41% vs 50%. The intergroup trial demonstrate that better local control improve survival if radiation fields include stamps, tumour bed, proximal nodal chains and nodes corresponding to D2 extended lymph nodes dissection. Treatment was feasible with few severe toxic effects (1%). Of the 281 patients, 17% stopped treatment because toxic effects. Technical modalities of radiotherapy and post-operative nutrition support, which are critical points of interest for this treatment, are also discussed.

Comparison of intraoperative radiation therapy-containing multimodality treatment with historical treatment modalities for locally recurrent rectal cancer

PURPOSE

Treatment protocols for patients with locally recurrent rectal cancer have changed in the last two decades. Subsequently, treatment goals shifted from palliation to possible cure. In this retrospective study, we explored the treatment variables that may have contributed to the improvement in outcome by comparing three treatment modalities from two collaborating institutions in patients with similar tumor characteristics.

METHODS

Ninety-four patients were treated with electron-beam radiation therapy only (1975-1990), 19 with combined preoperative electron-beam radiation therapy and surgery (1989-1996), and 33 with intraoperative radiation therapy-multimodality treatment (1994-1999). Intraoperative radiation therapy was delivered either as intraoperative electron-beam radiotherapy (10-17.5 Gy) in 20 patients or as intraoperative high-dose-rate brachytherapy (10 Gy) in 13 patients. No patient had received prior electron-beam radiation therapy.

RESULTS

The three-year survival, disease-free survival, and local control rates were 14, 8, and 10 percent, respectively, in the electron-beam radiation therapy-only group and 11, 0, and 14 percent, respectively, in the combined electron-beam radiation therapy-surgery group. The overall intraoperative radiation therapy-multimodality treatment group showed significantly better three-year survival, disease-free survival, and local control rates of 60, 43, and 73 percent, respectively, compared with the historical control groups (P < 0.001).

CONCLUSION

The outcome of patients with locally recurrent rectal cancer was improved after the introduction of intraoperative radiation therapy-multimodality treatment.

Phase II trial of adjuvant radiation and intraperitoneal 5-fluorouracil for locally advanced colon cancer: results with 10-year follow-up

PURPOSE

To determine the toxicity, disease-free survival, and overall survival for patients with Modified Astler-Coller (MAC) B2-3 or C1-3 colon cancer receiving adjuvant radiation and sequential intraperitoneal 5-fluorouracil (5-FU).

METHODS AND MATERIALS

From August 1984 to June 1989, 45 patients were accrued to this Phase II trial and received a 21-week course of intraperitoneal 5-FU (20 mg/kg/d x 5) and external beam radiation. The radiation was delivered to the tumor bed and para-aortic lymph nodes in two split-courses of 22.5 Gy, alternating with the first two cycles of chemotherapy. All patients then received 4 additional cycles of intraperitoneal 5-FU.

RESULTS

The therapy was well tolerated with 4 patients experiencing Grade 3 peritonitis. Four patients developed small bowel obstruction requiring surgery; in each instance, recurrent tumor was found at the time of laparotomy. The median and overall survivals at 10 years were 9.3 months and 53% respectively. Local failures were infrequent, occurring in only 11% of patients treated.

CONCLUSIONS

Sequential intraperitoneal 5-FU and tumor-bed/para-aortic irradiation is tolerable in patients with resected colon cancer. Although the incidence of local and regional relapse appeared to be lower than anticipated, this did not appear to translate into improved survival.

Feasibility and first results of multimodality treatment, combining EBRT, extensive surgery, and IOERT in locally advanced primary rectal cancer

PURPOSE

To assess the outcome of aggressive multimodality treatment with preoperative external beam radiation therapy (EBRT), extended circumferential margin excision (ECME) and intraoperative electron beam radiation therapy (IOERT) in patients with locally advanced primary rectal cancer.

METHODS AND MATERIALS

Thirty-eight patients with primary locally advanced rectal cancer, but without distant metastases, received multimodality treatment. CT-scan showed extension to other structures in 15 patients (39%) and definite infiltration into the surrounding structures in 23 patients (61%). All patients received preoperative EBRT (dose range 25-61 Gy) and 82% received 50.4 Gy. The resection types were: 12 low anterior resections (31%), 14 abdomino-perineal resections (37%), 6 abdomino-transsacral resections (16%), and 6 pelvic exenterations (16%). The IOERT dose ranged from 10 to 17.5 Gy depending on the completeness of the resection.

RESULTS

There was no perioperative mortality. The resection margins were microscopically negative in 31 patients (82%), microscopically positive in 4 (10%), and positive with gross residual disease in 3 patients (8%). Pelvic recurrences were observed in 5 patients (13%) including 3 IOERT infield failures. The overall 3-year local control, disease-free survival (DFS), and survival rates were 82%, 65%, and 72%, respectively. Negative resection margins were the most significant prognostic factor with regard to DFS (p = 0.0003) and distant control (p = 0.002) compared with cancer involved surgical margins.

CONCLUSION

A high percentage of curative resections can be achieved in this group of patients with locally advanced rectal cancers. Adding IOERT to preoperative EBRT and ECME achieves high local control rates and possibly improves survival.

Results of irradiation or chemoirradiation following resection of gastric adenocarcinoma

PURPOSE

To evaluate the results of postoperative irradiation +/- chemotherapy for carcinoma of the stomach and gastroesophageal junction.

METHODS AND MATERIALS

The records of 63 patients who underwent resection for stomach cancer were retrospectively reviewed. Twenty-five patients had complete resection with no residual disease but with high-risk factors for relapse. Twenty-eight had microscopic residual and 10 had gross residual disease. Doses of irradiation ranged from 39.6 to 59.4 Gy with a median dose of 50.4 Gy in 1.8 Gy fractions. Fifty-three of the 63 (84%) patients received 5-fluorouracil (5-FU)-based chemotherapy.

RESULTS

The median duration of survival was 19.3 months for patients with no residual disease, 16.7 months for those with microscopic residual disease, and 9.2 months for those with gross residual disease (p = 0.01). The amount of residual disease also significantly impacted locoregional control (p = 0.04). Patients with linitis plastica did significantly worse in terms of survival, locoregional control, and distant control than those without linitis plastica. The use of 4 or more irradiation fields was associated with a significant decrease in the rate of Grade 4 or 5 toxicity when compared to the patients treated with 2 fields (p = 0.05).

CONCLUSIONS

There was a significant association between survival and extent of residual disease after resection as well as the presence of linitis plastica. Distant failures are common and effective systemic therapy will be necessary to improve outcome. The toxicity of combined modality treatment appears to be reduced by using greater than 2 irradiation fields.

Indications for and results of combined modality treatment of colorectal cancer

Combined modality chemoirradiation is commonly used as a component of treatment in combination with maximum resection for both high-risk resectable and locally advanced primary or recurrent rectal cancers. With surgically resected but high-risk rectal cancers, postoperative chemoirradiation has been shown to improve both disease control (local and distant) and survival (disease-free and overall) and was recommended as standard adjuvant treatment at the 1990 National Institute of Health (NIH) Consensus Conference on Adjuvant treatment for patients with rectal and colon cancers. Subsequent intergroup trials are being conducted to help define optimal combinations of postoperative chemoirradiation for resected high-risk rectal cancers and to test sequencing issues of preoperative versus postoperative chemoirradiation. With locally unresectable primary or recurrent colorectal cancers, standard therapy with surgery, external beam irradiation (EBRT) and chemotherapy is often unsuccessful. When intraoperative electron irradiation (IOERT) is combined with standard treatment, local control and survival appear to be improved in separate analyses from the Mayo Clinic and the Massachusetts General Hospital (MGH). However, routine use of systemic therapy is also needed as a component of treatment, in view of high rates of systemic failure.

[Intraoperative radiotherapy in 1997]

Intra Operative Radiation Therapy (IORT) has been routinely used for the past 20 years. It is a feasible treatment, with a reasonable cost and an acceptable acute and late toxicity. There is so far no strong randomized trial demonstrating that IORT can improve overall survival. Nevertheless, in many institutions it is recognized as an efficient treatment in selected patients. In case of locally recurrent disease an incomplete gross resection is often the only choice; IORT in such a situation has led to very encouraging results. For locally advanced deep seated primary tumors IORT seems to improve local control. In the near future IORT should be used on a larger and stronger basis. The manufacturing of new mobile linac should allow more surgeons to perform IORT and to conduct clinical trials to confirm the present indications in cancers with high local malignancy.