PLA2 (group IIA phospholipase A2) as a prognostic determinant in stage II colorectal carcinoma.
BACKGROUND
Approximately 30% of all colorectal cancer (CRC) patients are diagnosed with stage II disease. Adjuvant therapy is not widely recommended. However, it is well established that a subgroup of patients with stage II are at high risk for recurrence within their lifetime and should be considered for adjuvant chemotherapy. The present work was designed to assess the value of group IIA phospholipase A2 (PLA2) as a predictor of disease outcome in stage II CRC patients with long-term follow-up.


METHODS
The present study comprises a series of 116 patients who underwent bowel resection for stage II CRC during 1981-1990 at Turku University Hospital. Archival paraffin-embedded CRC tissue samples were used to prepare tissue microarray blocks for immunohistochemical staining with PLA2.


RESULTS
Fifty-five percent of all tumors were positive for PLA2. There was no significant correlation between PLA2 expression and age, sex, depth of invasion and lymph node status. In Kaplan-Meier survival analysis, there was a significant (P = 0.010) difference in disease-free survival (DFS) between patients with negative tumors (longer DFS) and those with positive tumors. The same was true with disease-specific survival (DSS), patients with PLA2-negative tumors living significantly longer (P = 0.025). In multivariate (Cox) survival analysis, however, PLA2 was not an independent predictor of DFS or DSS. In subgroup analysis, the right-sided tumors with negative PLA2 staining had remarkably better prognosis (P = 0.010) than PLA2-positive left-sided tumors.


CONCLUSIONS
Quantification of PLA2 expression seems to provide valuable prognostic information in stage II CRC, particularly in selecting the patients at high risk for recurrent disease who might benefit from adjuvant therapy.
Buhmeida
A
A
Department of Oncology and Radiotherapy,Turku University Hospital, University of Turku, Turku, Finland. abuhme@utu.fi
Bendardaf
R
R
Hilska
M
M
Laine
J
J
Collan
Y
Y
Laato
M
M
Syrjänen
K
K
Pyrhönen
S
S
D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D018450:Disease Progression; D018572:Disease-Free Survival; D005387:Finland; D005500:Follow-Up Studies; D054501:Group II Phospholipases A2 / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D046228:Microarray Analysis; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
D054501:Group II Phospholipases A2; C516287:PLA2G2A protein, human