A prospective study on lymph nodal harvest in fresh, non-fixed, wet specimen of colonic malignancy.

BACKGROUND OF STUDY

Colo-rectal adenocarcinoma is one of the most common malignant tumors world wide .

In non metastatic colorectal malignancies, one of the most important  prognostic factors is the number of lymph nodes ( NLN) examined in the pathological specimen whether positive or negative and it correlates closely with the survival of the patient.

When performing mesorectal and mesocolic excision for rectal and colon cancer, it is crucial to encompass the draining nodal basins for staging and, possibly, therapeutic purposes.

Guidelines recommended a cut off of 12 lymph nodes harvested is considered adequate.yet the evidence for such is questionable as it is unclear whether an increasing the LN count results in improved survival.

A better focus of guidelines and communication between pathologist and surgeon is a main determinant of  rise in NLN

The pursuit of a sufficient LN harvest represents good clinical  practice; however, recent evidence shows that the exhaustive searching for very high LN yields may be unnecessary and has little influence on modern approaches to treatment.

STUDY SETTING: Regional Cancer Centre, Trivandrum.

STUDY POPULATION:Patients undergoing colectomy in RCC for biopsy proven adenocarcinoma of colon .

SAMPLE SIZE

50 cases

PERIOD OF STUDY: 2 Year

METHODOLOGY

Specimen  is collected in the operating room immediately following surgery.

The same is examined before immersing into the formalin.

Dissection of the specimen is done in the presence of a pathologist to retrieve the lymph nodes from the specimen.

Visual and palpatory method is used for identification of the nodes.

The lymph node stations are harvested and numbered using Japanese Society of Colorectal Cancer Classification.

Lymph nodes are mounted on a pre prepared chart to label their location/station.

STATISTICAL ANALYSIS

The number of node positivity among the total number of nodes retrieved.

The number of LNs examined per patient will be the main endpoint of interest. Mean and median numbers of LNs examined according to individual patient characteristics will be estimated for patients with colon cancer . Poisson regression will be used to model the number of LNs retrieved as a function of pathological and clinical factors( age, sex, tumor stage,grade and location) and to identify significant predictors of LN retrieval. Regression coefficients in Poisson regression are logâ€risk ratios and, thus, are useful for interpretation.

References

• 1. Compton CC, Fielding LP, Burgart LJ, Conley B, Cooper HS, Hamilton SR, Hammond ME, Henson DE, Hutter RV, Nagle RB, et al. Prognostic factors in colorectal cancer. College of American Pathologists Consensus Statement 1999. Arch Pathol Lab Med. 2000;124:979–994.

2.   Baxter NN, Virnig DJ, Rothenberger DA, Morris AM, Jessurun J, Virnig BA. Lymph node evaluation in colorectal cancer patients: a population-based study. J Natl Cancer Inst. 2005;97:219–225.

3.   O’Dwyer ST, Haboubi NY, Johnson JS, Gardy R. Detection of lymph node metastases in colorectal carcinoma. Colorectal Dis. 2001;3:288–294.

4.Le Voyer TE, Sigurdson ER, Hanlon AL, Mayer RJ, Macdonald JS, Catalano PJ, Haller DG. Colon cancer survival is associated with increasing number of lymph nodes analyzed: a secondary survey of intergroup trial INT-0089. J Clin Oncol. 2003;21:2912–2919.

5.  Tsai HL, Lu CY, Hsieh JS, Wu DC, Jan CM, Chai CY, Chu KS, Chan HM, Wang JY. The prognostic significance of total lymph node harvest in patients with T2-4N0M0 colorectal cancer. J Gastrointest Surg. 2007;11:660–665.