Adjuvant and neoadjuvant chemoradiation or radiotherapy in rectal cancer--a review focusing on open questions

Recent advances in multidisciplinary approach for rectal cancer

Surgery is a major treatment option for rectal cancer, and total mesorectal excision has been demonstrated to be advantageous in terms of oncological outcome and thus has been the standard surgical approach. Radiotherapy before or after radical surgery is the optimal treatment to control local recurrence of advanced rectal cancer. To date, in many countries, the combination of neoadjuvant concurrent chemotherapy and radiotherapy is considered the standard therapy. A more recent interest in neoadjuvant therapy has been the use of oxaliplatin or targeted agents for neoadjuvant chemoradiotherapy. However, despite many trials of oxaliplatin and targeted agents, 5-FU-based concurrent chemoradiotherapy has remained the only standard treatment option. Postoperative adjuvant chemotherapy with neoadjuvant chemoradiotherapy or induction chemotherapy with neoadjuvant chemoradiotherapy may further improve patient survival, as some clinical studies recently indicated. In Japan, neoadjuvant therapy is not the standard treatment method, because surgery with lateral lymph node dissection is usually performed and this type of surgery may reduce recurrence rate as does radiation therapy. The phase III study to evaluate the oncological effect of the Japanese standard operation (mesorectal excision, ME) with lateral lymph node dissection in comparison with ME alone for clinical stage II and III lower rectal cancer is currently ongoing.

Current practice in preoperative therapy and surgical management of locally advanced rectal cancer: a bi-national survey

AIM

The Australasian colorectal surgeon's current approach to preoperative rectal cancer management was compared with international guidelines.

METHOD

Members of the Colorectal Surgical Society of Australia and New Zealand were surveyed in 2010, on the use of MRI and the management of locally advanced rectal cancer. Surgeons had to decide the appropriate management in five scenarios that were developed from national guidelines.

RESULTS

Of 174 invitations sent, 108 (62.1%) replies were received. Most surgeons (98.1%) had access to MRI. Ninety-three (86.1%) would use MRI routinely for staging. The majority selected a tumour-specific mesorectal resection for upper rectal cancer (58.2%) and a total mesorectal excision for distal cancer (100%). Almost all restorative operations included a covering ileostomy. One third of surgeons recommended that patients with a favourable cT3 mid-rectal tumour (N0, clear circumferential resection margins) should not have preoperative therapy and should proceed directly to surgery. When high-risk features, such as threatened resection margins or cN1 stage, were present, 5% and 15% of surgeons, respectively, would continue to treat by standard resection without preoperative therapy.

CONCLUSION

Evidence-based international guidelines for the management of rectal cancer have changed little in the last 10 years. Despite this, there is a clear gap between these and clinical practice. The main variance relates to the role of radiotherapy in locally advanced rectal cancer. Despite considerable evidence that radiotherapy reduces local recurrence for all stages of rectal cancer, current practice in Australasia is for its selective use.

Stage-to-stage comparison of preoperative and postoperative chemoradiotherapy for T3 mid or distal rectal cancer

PURPOSE

To investigate, in a comparative analysis, the prognostic implications of postchemoradiotherapy (post-CRT) pathologic stage (ypStage) vs. postoperative pathologic stage (pStage) in rectal cancer.

METHODS AND MATERIALS

Between May 2001 and December 2006, 487 patients with T3 mid or distal rectal cancer were analyzed retrospectively. Concurrent CRT was administered preoperatively (n = 364, 74.7%) or postoperatively (n = 123, 25.3%). The radiation dose was 50.4 Gy in 28 fractions. All patients underwent a total mesorectal excision and received adjuvant chemotherapy. Disease-free survival (DFS) was estimated using the Kaplan-Meier method. Differences in DFS, stratified by ypStage and pStage, were compared using the log-rank test.

RESULTS

For surviving patients, the median follow-up period was 68 months (range, 12-105 months). The 5-year local recurrence-free survival rate was not different, at 95.3% and 92.1% in preoperative and postoperative CRT groups, respectively (p = 0.402), but the 5-year distant metastasis-free survival rate was significantly different, at 81.6% (preoperative CRT) vs. 65.4% (postoperative CRT; p = 0.001). The 5-year DFS rate of 78.8% in the preoperative CRT group was significantly better than the 63.0% rate in the postoperative CRT group (p = 0.002). Post-CRT pathologic Stage 0-I occurred in 42.6% (155 of 364) of the patients with preoperative CRT. The 5-year DFS rates were 90.2% (ypStage 0-I), 83.5% (ypStage II), 77.3% (pStage II), 58.6% (ypStage III), and 54.7% (pStage III). The DFS rate of ypStage 0-I was significantly better than that of ypStage II or pStage II. Post-CRT pathologic Stage II and III had similar DFS, compared with pStage II and III, respectively.

CONCLUSIONS

Disease-free survival predicted by each ypStage was similar to that predicted by the respective pStage. Improved DFS with preoperative vs. postoperative CRT was associated with the ypStage 0-I group that showed a similarly favorable outcome to pStage I rectal cancer.

Morphology and prognostic value of tumor budding in rectal cancer after neoadjuvant radiotherapy

Tumor budding is an acknowledged prognostic marker in colorectal cancer. This study was conducted to investigate the morphology and prognostic significance of budding in rectal cancer after neoadjuvant radiotherapy. Surgical specimens from 96 consecutive patients who underwent neoadjuvant radiotherapy and curative resection were retrieved to assess budding and other clinicopathologic factors. The morphology and prognostic significance of postirradiation tumor budding were closely associated with tumor regression grade. In the tumor regression grade 1 group, tumor budding presented as "false budding" and did not have a significant association with prognosis. In the tumor regression grade 2 and 3 groups, budding was observed surrounded by radiation-induced fibrosis and large populations of infiltrating inflammatory cells, and budding intensity was significantly associated with histologic differentiation, ypN stage, and lymphovascular invasion (P < .05). Moreover, the low-grade budding subgroup showed a significantly higher rate of 5-year disease-free survival than the high-grade budding subgroup (87.5% versus 55.6%, P < .0001). Multivariate analysis showed that pretreatment serum carcinoembyronic antigen, tumor regression grade, and tumor budding were the major independent factors affecting long-term disease-free survival. In conclusion, postirradiation budding has distinct morphology and prognostic significance in rectal cancer after neoadjuvant radiotherapy.

A phase I/II study of neoadjuvant chemotherapy with Pemetrexed (Alimta) in rectal cancer

AIM

The aim was to assess the feasibility of preoperative chemotherapy and possible tumour response using Pemetrexed (Alimta) in rectal cancer.

METHOD

The study was a prospective, non-randomized, single-centre phase I/II feasibility trial. 37 patients with resectable rectal cancer were recruited and given three 3-week cycles of preoperative Pemetrexed therapy. Tumour size and stage were assessed by MRI scans before and after chemotherapy. Treatment tolerability and response such as changes in tumour size and symptoms were assessed.

RESULTS

All patients completed the chemotherapy. Whilst mild side effects were frequent (grade 1, 34/37), the risk of severe effects was limited (grade 3 or 4, 4/37). Overall, there was a significant reduction in tumour size (p < 0.001). By RECIST criteria, one patient had tumour progression, 23/36 had stable disease and 12 patients had a response of up to 65%. There was also a significant decrease in the number of pre-treatment symptoms (p < 0.018) including reduction of bleeding and diarrhoea/constipation.

CONCLUSION

Preoperative (Neoadjuvant) treatment with Pemetrexed was feasible in studied patients. Serious side effects were limited and a radiological tumour response or stable disease was seen in a majority of patients.

Individualized magnetic resonance imaging-based neoadjuvant chemoradiation for middle and lower rectal carcinoma

AIM

In most institutions neoadjuvant chemoradiation for middle and lower rectal carcinoma is currently given to patients with tumours of clinical stages II or III (cT3,4 and/or N1,2). The possibility of a reduction in the use of neoadjuvant chemoradiation by an individualized magnetic resonance imaging (MRI)-based indication for neoadjuvant chemoradiation was analysed.

METHOD

Assessment of the pathological and oncological principles indicating for neoadjuvant treatment was used to determine the prognostic importance of the distance between the tumour and the circumferential resection margin and pretherapeutic assessment using modern MRI.

RESULTS

Based on the results of pretreatment MRI scanning, a proposal is presented for the treatment of middle and lower rectal carcinoma with neoadjuvant chemoradiation. Adopting this proposal, the frequency of neoadjuvant chemoradiation decreased from 70% to 35% and the early and late adverse effects of this therapy were reduced. In contrast, the expected locoregional recurrence rate increased from 6% to 11% if all quality criteria were met and to 18% if not.

CONCLUSION

An MRI-based indication for neoadjuvant chemoradiation is justified only for centres with regular quality assurance of MRI, surgery, radiotherapy and pathology. The proposal needs confirmation by long-term follow up and by prospective studies with larger numbers of patients.

Regional lymph node metastasis and locoregional recurrence of rectal carcinoma in the era of TME [corrected] surgery. Implications for treatment decisions

BACKGROUND AND AIMS

For rectal carcinoma treated according to the concept of total mesorectal excision (TME surgery), the independent influence of regional lymph node metastasis on the locoregional recurrence risk is still in discussion. A reliable assessment of this risk is important for an individualised selective indication for neoadjuvant radio-/radiochemotherapy.

METHODS

Analysis of literature, especially of the last 20 years, and consideration of pathological and oncological basic research. Multivariate analysis of data of the Erlangen Registry of Colorectal Carcinoma.

RESULTS

The clinical assessment of the pretherapeutic regional lymph node status by the present available imaging methods is still unreliable. The analysis of the association between pretherapeutic regional lymph node status and locoregional recurrence risk has to be based on follow-up data of patients treated by primary surgery and has to be distinguished between patients treated by conventional and optimised quality-assured TME surgery, respectively. Data from Erlangen show an increase of the local recurrence risk for patients with at least four involved regional lymph nodes.

CONCLUSIONS

For patients with at least four involved regional lymph nodes, a neoadjuvant radiochemotherapy may be indicated. However, today, the pretherapeutic diagnosis is uncertain and results in overtherapy in 40%. Thus, in case of positive lymph node findings by imaging methods, the benefits and risk of neoadjuvant therapy in such situations should always be discussed with the patient in the sense of informed consent and shared decision.

Effects of CO(2) pneumoperitoneum on anastomotic healing in rats receiving preoperative 5-fluorouracil neoadjuvant chemotherapy

BACKGROUND

When used separately, antineoplastic agents and carbon dioxide (CO(2)) pneumoperitoneum have been reported to impair anastomotic healing in experimental animals. However, the effects of their combined use have not been previously investigated. The aim of this study was to investigate the possibility that neoadjuvant chemotherapy with 5-fluorouracil followed by CO(2) pneumoperitoneum would affect the healing of anastomoses in the colon.

METHODS

Sprague-Dawley rats (n = 48) were given 5-fluorouracil (20 mg/kg/day) for 5 days, and were then assigned to one of the three groups. Prior to surgery, the control group received no pneumoperitoneum. The other two groups received pneumoperitoneum at 6 and 12 mmHg, respectively, for 2 hr. The large intestine was transected and anastomosis was performed via median laparotomy. On postoperative days 3 and 7, relaparotomy was performed in half of the rats in each group. From the colon, a segment including the anastomosis was excised. Tissue hydroxyproline levels were measured. For histological evaluation, the Verhofstad scale was modified and used.

RESULTS

No significant differences in hydroxyproline levels were seen across the groups on postoperative days 3 or 7. However, by postoperative day 7, polymorphonuclear leukocytes and necrosis in the 6-mmHg group had decreased markedly, and granulation had improved.

CONCLUSION

Overall, these findings suggest that preoperative 5-fluorouracil therapy followed by pneumoperitoneum at 6 or 12 mmHg does not impair anastomotic healing.