Dr George Awwad and colleagues from Australia performed a literature review was performed to elucidate whether long-course preoperative radiotherapy for patients with rectal cancer affects lymph node yield, and whether this influences prognosis.
Cochrane Database, PubMed/MEDLINE, Scopus, Web of Knowledge, Embase and CINAHL databases and reference lists from published journal articles published between 1 January 1990 and 30 June 2011 were searched.
Studies examining lymph node yield and prognosis were selected for review.
|5-year survival was 69% in those with more than 11 lymph nodes |
The researchers found that 1029 articles, of which 11 met the inclusion criteria.
None was a randomized controlled trial and all were cohort studies.
The team noted that 4 studies showed that long-course preoperative radiotherapy reduced lymph node yield.
However only 1 demonstrated a statistically significant survival benefit in patients with higher lymph node yields.
The resesarch team found that 5-year survival was 48% in patients with fewer than, and 69% in those with more than 11 lymph nodes identified in the operative specimen.
Dr Awwad's team concludes, "Whilst long-course preoperative radiotherapy appears to reduce lymph node yield in patients with rectal cancer, no causal relationship between lymph node yield and survival can be established in this group of patients."