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. 2011 Jul-Aug;4(4 Suppl 1):S24.

Chemoradiotherapy in Rectal Cancer: Clinical Do's and Don'ts

PMCID: PMC3283010
Gastrointest Cancer Res. 2011 Jul-Aug;4(4 Suppl 1):S24.
Christopher Crane 1

ABSTR 1035 – Oral Presentation

Combined-modality therapy was established as the standard of care based on two randomized trials in 1991 at a National Cancer Institute Consensus Conference. Since that time, the role of chemoradiotherapy has been called into question in selected patients. There is clearly a possibility of risk stratification based on T and N stage and distance from the anal verge. For the majority of patients, local control benefit afforded by chemoradiotherapy is modest. Therefore, efforts should also focus on the reduction of acute and long-term toxicity.

If chemoradiotherapy is clearly indicated, such as in low rectal cancers with T3/4 or node-positive disease, it should be given preoperatively, based on results from the German Intergroup Trial, which showed a local tumor control benefit, with lower rates of acute and late toxicity as well as a sphincter preservation benefit. Acute toxicity management is a critical component of care. Patients should have concurrent chemotherapy held for grade 2 or greater nonhematologic toxicity and radiotherapy should be continued.

Intensity-modulated radiotherapy (IMRT) could have a role in selected patients, but its ability to reduce GI toxicity is unclear. The most significant benefit of IMRT may be in the lower pelvis when the inguinal nodes are treated, because it allows the genitalia to the spared. In addition, the use of a simultaneous in-field boost to 63 Gy can definitively treat small lymph nodes while delivering a microscopic preoperative dose of 45–50.4 Gy to radiographically negative nodal basins at risk.

Favorable factors predictive of local tumor control in patients treated with surgery alone include negative nodes, greater distance from the anal verge, focal penetration of the rectal wall, and at least a 2 mm radial margin. Also, 14 nodes are considered adequate for the assessment of nodal involvement. Future trials will be focused on neoadjuvant chemotherapy without radiotherapy in patients with intermediate and moderately high risk for local recurrence with surgery alone (such as T2N1 and T3N0 tumors in the mid and high rectum).

Gastrointest Cancer Res. 2011 Jul-Aug;4(4 Suppl 1):S24.

Expression of PTEN During Preoperative Radiotherapy Combined With Capecitabine Chemotherapy in Chinese Patients With Locally Advanced Rectal Cancer

Daoyuan Wang 1

ABSTR 1036 – Proffered Oral Presentation

Objective:

To evaluate the efficacy and safety of capecitabine combined with preoperative radiotherapy (RT) in Chinese patients with locally advanced rectal cancer (LARC) and observe the expression of phosphatase and tensin homolog (PTEN) in cancer tissue before and after neoadjuvant chemoradiotherapy (NCT).

Patients and Methods:

Between June 2005 and June 2008, 66 patients with LARC were treated with capecitabine (825 mg/m2 twice daily) and concurrent RT (50 Gy/25 fractions, 5 days per week). Patients underwent surgery after 6–8 weeks of combined therapy, followed by four cycles of adjuvant capecitabine (1,250 mg/m2, twice daily on days 1–14, every 3 weeks). The primary end point was the rate of pathologic complete response (pCR). The expression of PTEN was detected before and after NCT.

Results:

Sixty-one patients (92.4%) completed the NCT course as initially planned. The most severe hematologic adverse event was leukopenia, which occurred with grade 2 intensity in 13 (19.7%) patients and grade 3 in 3 (4.5%) patients. Grade 3 diarrhea and hand-foot syndrome (HFS) were observed in 3 (4.5%) and 2 (3.0%) patients, respectively. However, no grade 4 toxicity was observed. There were no treatment-related deaths during this study. Of the 64 patients treated with surgery, all had radial margins (R0 resections). Among the 32 patients with the primary tumor ≤5 cm from the anal verge, 20 (62.5%) underwent sphincter-preserving surgical resections. pCR was found in 10 patients (15.6%). PTEN mRNA expression in the cancer tissues after NCT was significantly higher than before NCT (P = .008). Meanwhile, the result of western blot demonstrated that PTEN protein expression in the cancer tissues after NCT was significantly higher than before NCT (P = .027).

Conclusions:

Preoperative chemoradiotherapy with capecitabine and RT appears to be a safe, well-tolerated, and effective neoadjuvant treatment modality for LARC, which can also increase the PTEN expression level in cancer tissues and promote the apoptosis of cancer cell.

Articles from Gastrointestinal Cancer Research : GCR are provided here courtesy of International Society of Gastrointestinal Oncology

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