Die Rolle der Magnetresonanztomographie für die Indikationsstellung zur präoperativen Therapie beim Rektumkarzinom

Prediction of survival after neoadjuvant therapy in locally advanced rectal cancer - a retrospective analysis

Purpose

The aim of this retrospective analysis was to determine if the response to preoperative radio(chemo)therapy is predictive for survival among patients with locally advanced rectal cancer and may act as a potential surrogate endpoint for disease free survival and overall survival.

Results

Eight hundred seventy-eight patients from five centers were analyzed. There were 304 women and 574 men; the median age was 64.7 years. 77.6% and 22.4% of patients received neoadjuvant radiochemotherapy or short-course radiotherapy, resulting in a pathological complete response in 7.3%. T-downstaging and N-downstaging occurred in 50.5% and 37% of patients after neoadjuvant therapy. In patients with T-downstaging, the 10-year DFS and 10-year OS were 64.8% and 66.8% compared to 37.1% and 45.9% in patients without T-downstaging. N-downstaging resulted in 10-year DFS and 10-year OS in 56.2% and 62.5% compared to 47.3% and 52.3% without N-downstaging. Based on routinely evaluated clinical parameters, an absolute risk prediction calculator was generated for 5-year disease-free survival, and 5-year overall survival.

Conclusion

T-downstaging and N-downstaging after neoadjuvant radiochemotherapy or short-course radiotherapy resulted in better DFS and OS compared to patients without response. Based on clinical parameters, 5-year DFS, and 5-year OS can be predicted using a prediction calculator.

Intensified preoperative chemoradiation by adding oxaliplatin in locally advanced, primary operable (cT3NxM0) rectal cancer : Impact on long-term outcome. Results of the phase II TAKO 05/ABCSG R‑02 trial

Purpose

The major goals of preoperative treatment for locally advanced rectal cancers (LARCs) are improvement of local tumor control, tumor downsizing, and downstaging. Modifications with respect to standardized chemoradiation protocol, e. g., integrating oxaliplatin, are realized with the aim of improving primary tumor response and patient outcome.

Patients and methods

In this phase II multicenter study, patients with LARC of the mid- or lower rectum, cT3cNxcM0 as staged by MRI, were included and treated preoperatively with a combination of capecitabine and oxaliplatin following a standardized protocol during radiation. The focus of this long-term analysis was overall (OS) and disease-free survival (DFS).

Results

A total of 60 patients (19 women, 41 men, median age 60.5 years) were initially enrolled, 1 patient was excluded (violation of study protocol), and 1 was patient lost of follow-up, leading to a total of 58 patients for long-term analysis. The 3‑year OS was 85.5%; 3‑year DFS 71.2%. Over time, 15 patients (25.9%) developed tumor recurrence (1 locoregional, 6.7%; 11 distant, 73.3%; 3 locoregional+distant, 20%). Recurrence-specific therapy was planned in the majority of patients, in 9 of 15 patients (60%) with a radical surgical approach. Of these, 4 patients (44.4%) are again tumor-free at the end of investigation. While tumor downsizing (T level) or pathologically complete response did not influence patient survival, lymph node negativity (LNneg) after preoperative chemoradiation showed significant influence.

Conclusion

LNneg after preoperative treatment for LARC significantly influences patient survival. A radical surgical approach for recurrent LARC (locoregional, distant) should be contemplated when possible as we were able to clearly demonstrate its importance and efficacy.

MRI-based treatment of rectal cancer: is prognostication of the recurrence risk solid enough to render radiation redundant?

BACKGROUND

Most current guidelines recommend neoadjuvant short course radiotherapy (sRT) or radio-chemotherapy (nRCT) for rectal cancer stage II and III. After the introduction of total mesorectal excision (TME) and magnetic resonance imaging (MRI), this proceeding has been questioned and omission of neoadjuvant treatment according to preoperative MRI-criteria has been propagated. Aim of the present paper is to review the state of evidence regarding MRI-based treatment decision depending on the predicted width of the circumferential resection margin (CRM).

METHODS

A comprehensive survey of the literature was performed using the search terms "rectal cancer", "radiotherapy", "radio-chemotherapy", "MRI-based therapy", "circumferential resection margin". Data from lately published observational studies were compared to results from randomized trials and outcome analyses of the Norwegian national cancer registry.

RESULTS

Only one observational study using MRI-based treatment according to the anticipated CRM provided 5 year local recurrence data, however only for 65 patients. The second study did not yet evaluate recurrence rates. Two randomized trials comparing sRT to primary TME showed significantly worse outcome for non-irradiated patients. Data from the Norwegian rectal cancer registry demonstrate that TME alone is associated with higher LRR than achievable with preoperative RT.

CONCLUSIONS

Current evidence does not support the omission of neoadjuvant treatment for stage II-III rectal cancer on the basis of an MRI-predicted negative CRM. Randomized studies are warranted to clarify whether and for which subgroups TME alone is safe in terms of local recurrences.

[Individualization of guidelines. Approach for rectal cancer in UICC stages II and III]

BACKGROUND

The German guidelines for the therapy of rectal carcinoma in Union Internationale Contre le Cancer (UICC) stages II and III raise questions of overtherapy. This is why we have individualized the therapy in suitable isolated cases (localization in the upper third of the rectum and wider safety margins in cases of small T3).

MATERIAL AND METHODS

All 131 patients with rectal cancer stages II and III, who were operated on within a time period of 4 years were retrospectively included in the study. In 30 favorable cases no radiotherapy was given and in 15 of these no chemotherapy. After an average of 57 months follow-up the course of the disease could be clarified in 95 % of the patients.

RESULTS

The 5-year survival rate in the whole group was 81.5 % with a local recurrence rate of 8 %. Of the patients with no additional therapy (or only adjuvant chemotherapy), 30 had a 5-year survival rate of 100 % (86.7 %) and a local recurrence rate of 6.7 % (6.7 %).

CONCLUSIONS

In this study it could be shown that an individualization of guidelines in special cases does not lead to a higher mortality rate or to a higher rate of local recurrence. The study highlights that chemotherapy and radiotherapy with all the negative consequences could be avoided for several patients.

Rectal cancer : when is the local recurrence risk low enough to refrain from the aim to prevent it?

Recently, preliminary results of the OCUM study (optimized surgery and MRI-based multimodal therapy of rectal cancer) were published and raised concern in the scientific community. In this observational study, the circumferential resection margin status assessed in preoperative MRI (mrCRM) was used to decide for either total mesorectal excision (TME) alone or neoadjuvant radiochemotherapy (nRCT). In contrast to current guidelines, neither T3 stage (with negative CRM) nor clinically positive lymph nodes were an indication for nRCT. Pathologically node-positive patients received chemotherapy (ChT). Overall, 230 patients were included, of whom 96 CRM-positive patients received nRCT. The CRM was accurately predicted in MRI, the rate of mesorectal plane resection was high. Recurrence rates have not yet been reported, but an impressive rate of down-staging for both T and N stage after nRCT was observed, while acute side effects were minimal. Nonetheless, the authors conclude that a substantial number of patients could be "spared severe radiation toxicity" and propagate their concept for prospectively replacing current guidelines. This is based on the hypothesis that CRM is a valid surrogate parameter for the risk of local recurrence and in case of a negative CRM, nRCT becomes dispensable. Moreover, it is assumed that lymph node status is no more relevant. Both assumptions are a contradiction to recent data from randomized studies as specified below. As 5-year locoregional recurrence rate (LRR) of only of 5-8% and < 5% in low risk rectal cancer can be achieved by the addition of RT, the noninferiority of surgery alone can not be presumed unless the expected 5-year LRR is ≤ 5-8%, whereas any excess of this range renders the study design inacceptable. Unless a publication explicitly specifies 5-year LRR, results are not exploitable for clinical decisions.

Neoadjuvant radiochemotherapy and surgery for advanced rectal cancer : prognostic significance of tumor regression

PURPOSE

Preoperative radiochemotherapy is widely used in the treatment of locally advanced rectal cancer. The predictive value of response to neoadjuvant treatment remains uncertain. We retrospectively evaluated the impact of downstaging and tumor regression as prognostic factors and its influence on the ability to perform sphincter-sparing surgery.

PATIENTS AND METHODS

A total of 72 consecutive patients with advanced rectal cancer were included in this retrospective analysis. All patients were treated with preoperative 5-fluorouracil-based chemotherapy and pelvic radiation with a total dose of 50.4 Gy followed by surgery 6 weeks later.

RESULTS

A sphincter-preserving procedure could be performed on 42 patients, and in all 72 patients complete resection (R0) was achieved. A pathological complete response (ypT0, ypN0) was achieved in 8 (11%) patients. None of the patients showing a complete pathological response relapsed or died during the follow-up period. At a median follow-up of 28 months, 65 patients were alive, none of these patients had local recurrence and 15 patients had metastatic disease. Patients showing a complete pathological response had a significantly better 2-year disease-free survival compared to patients with ≥10% residual tumor cells (p = 0.024). Patients < 65 years showed a significantly better response rate, compared with those > 65 years of age (p = 0.036). Acute toxicity was moderate.

CONCLUSION

Preoperative radiochemotherapy is an effective and safe treatment for patients with locally advanced rectal cancer. Pathological parameters after preoperative radiochemotherapy, including tumor regression grading, could be correlated with disease-free survival. The impact of tumor regression grading needs to be further validated in prospective clinical trials.

Novel Carcinoembryonic-Antigen-(CEA)-Specific Pretargeting System to Assess Tumor Cell Viability after Irradiation of Colorectal Cancer Cells

PURPOSE

To date, no valid imaging modality exists for early response prediction to neoadjuvant radiochemotherapy in carcinoembryonic-antigen-(CEA)-expressing rectal cancers (UICC stages II and III). It is hypothesized that the uptake of an anti-CEA antibody is directly related to the number of viable tumor cells and may be quantified by immuno-positron emission tomography (immuno-PET). Therefore, we evaluated a novel pretargeting system using TF2, a humanized bispecific trivalent monoclonal antibody (mAb), directed against CEA and the IMP-288-peptide, a hapten for binding radiometals for imaging. Uptake and kinetics of the pretargeting system were investigated in vitro prior to and after irradiation.

METHODS

TF2 was labeled with ¹³¹I and IMP-288 with ¹¹¹InCl₃. The colorectal cancer cell lines HT29, SW480, and T84 with known varying CEA expression were incubated (≤ 72 hours) with ¹³¹I-TF2 or the TF2-¹¹¹In-IMP-288 pretargeting system. Parallel cultures were irradiated with 2-10 Gy high-energy photons. Tracer uptake, proliferation, apoptosis, and CEA-RNA expression of cancer cells were investigated.

RESULTS

The uptake of tracers was dependent on CEA expression and cell count of the cell lines (uptake/10⁶ cells: 0.3% in HT29, 1.5% in SW480, and 14% in T84, p < 0.001). The TF2-¹¹¹In-IMP-288 pretargeting system showed a higher uptake after 4 and 72 hours compared to (131)I-TF2 in parallel cultures. Only in one cell line (SW480) an increased apoptosis after irradiation could be detected. Irradiation increased dose dependently both the specific uptake of ¹³¹I-TF2 and of the TF2-¹¹¹In-IMP-288 system (4-fold in HT29 and T84 after 10 Gy (72 hours), p < 0.001). These results were CEA-mRNA independent.

CONCLUSION

This novel pretargeting system allows the quantitative analysis of CEA-expressing colorectal cancer cells and represents a promising tool for evaluation of tumor cell viability after irradiation.

Preoperative oxaliplatin, capecitabine, and external beam radiotherapy in patients with newly diagnosed, primary operable, cT₃NxM0, low rectal cancer: a phase II study

PURPOSE

In patients with locally advanced rectal cancer (LARC), preoperative chemoradiation is known to improve local control, and down-staging of the tumor serves as a surrogate for survival. Intensification of the systemic therapy may lead to higher downstaging rates and, thus, enhance survival. This phase II study investigated the efficacy and safety of preoperative capecitabine and oxaliplatin in combination with radiotherapy.

PATIENTS AND METHODS

Patients with LARC of the mid and lower rectum, T₃NxM0 staged by MRI received radiotherapy (total dose 45 Gy) in combination with oral capecitabine (825 mg/m² twice a day on radiotherapy days; weeks 1-4) and oxaliplatin 50 mg/m² intravenously (days 1, 8, 15, and 22). Efficacy was evaluated as rate of tumor down-categorization at the T level.

RESULTS

A total of 59 patients were enrolled (19 women, 40 men; median age of 61 years) and all were evaluable for efficacy and toxicity. Down-categorization at the T level was observed in 53% with pathological complete response in 6 patients (10%). Actual total radiotherapy, oxaliplatin and capecitabine doses received were 97%, 90%, and 93% of the protocol-specified preplanned doses, respectively. Grade 3/4 toxicity was observed in 15 patients (25%). The most frequent was diarrhea (12%).

CONCLUSIONS

Preoperative chemoradiation with capecitabine and oxaliplatin is feasible in patients with MRI-proven cT₃ LARC. The only clinically relevant toxicity was diarrhea. Overall, efficacy of the multimodality treatment was good, but not markedly exceeding that of 5-FU- or capecitabine-based chemoradiation approaches.

Long-term outcomes and quality of life after rectal carcinoma surgery

Background

A cohort study was undertaken to investigate the long-term oncological outcome, late adverse effects and quality of life (QOL) after treatment for rectal cancer.

Methods

This was an analysis of prospectively collected data from 268 consecutive patients with rectal carcinoma treated between 1995 and 1997 at the Department of Surgery, University Hospital Erlangen, Germany.

Results

Median follow-up was 8·8 years. The overall 10-year survival rate was 48·1 per cent. Of 219 patients who had a curative resection, 67 developed recurrent disease and 13 had second malignancies. Seventy patients had either a permanent stoma or a late adverse effect. Anorectal dysfunction and small bowel obstruction were significantly more common among patients who had multimodal treatment (P &lt; 0·001 and P = 0·049 respectively). Analysis of QOL in 97 long-term survivors showed that receiving chemoradiotherapy, a permanent stoma and lower-third rectal carcinoma were associated with significantly worse outcomes on several measures.

Conclusion

Late adverse effects and recurrences occurred in a significant number of patients during long-term follow-up. QOL varied according to tumour location and treatment type.