Absence of prolactin gene expression in colorectal cancer

Comparative study of tumor markers in patients with colorectal carcinoma before and after chemotherapy

BACKGROUND

Colorectal carcinoma (CRC), the second leading cause of cancer-related deaths in US, has a rising time-trend in India. Tumour markers in CRC are extensively researched, and there's still debate on their diagnostic and prognostic values.

METHODS

In this hospital-based longitudinal study in north India, 51 male diagnosed CRC cases (pre-chemotherapy) were contrasted against 50 age and sex matched controls. Nine biomarkers: carcinoembryonic antigen (CEA), prolactin (PRL), alfa feto protein (AFP), total human chorionic gonadotropin (hCG), cancer antigen-125 (CA-125), serum testosterone, prostate specific antigen (PSA) and ferritin were measured by direct chemiluminescence technique. Further, follow-up was done on 47 cases after treatment with six cycles of 5-flurouracil (5-FU) and oxaliplatin.

RESULTS

Mean serum CEA (case: 5.94±8.27 ng/mL, control: 2.5±0.79 ng/mL, P<0.05), PRL (case: 28.12±13.39 ng/mL, control: 14.24±13.13 ng/mL, P<0.0001), AFP (case: 10.9±6.65 ng/mL, control: 4.02±1.26 ng/mL, P<0.0001) levels were significantly raised in CRC cases compared to controls. On the contrary, mean testosterone level (P<0.05) was lower among the cases. After chemotherapy, the mean serum CEA (P<0.05), AFP (P<0.0001) and CA-125 (P<0.05) levels among the cases decreased significantly compared to their pretreatment levels.

CONCLUSIONS

The present study strongly indicates the role of CEA, PRL, AFP, CA-125 and testosterone as important biomarkers in male CRC patients from north India. Further, AFP, CA-125 and CEA may be used to assess the effectiveness of chemotherapy in such patients.

The relationship between gravidity and parity and colorectal cancer risk

OBJECTIVES

The influence of hormonal changes caused by pregnancy has been well studied in relation to colorectal cancer risk, but the association remains undefined. The purpose of this investigation was to examine in a case-control study the relationship between differences in gravidity and parity and colorectal cancer risk and if the association varied by microsatellite instability (MSI), a feature more common in women.

METHODS

The study population included incident colorectal cancer patients (n = 1014), aged 50-74 years, diagnosed in 1998-2002 in Washington state and controls (n = 1064) randomly selected from population lists. All study subjects completed telephone interviews to ascertain prior pregnancies, live births, and other covariates. Case tissue samples were obtained for MSI analyses. Multivariable logistic regression models estimated odds ratios (OR) and 95% confidence intervals (CI), adjusting for age, family history of colorectal cancer, body mass index (BMI), education, endoscopy screening, oral contraceptive use, hormone therapy use, smoking, and alcohol consumption.

RESULTS

There was an approximate 30%-50% reduction in risk of colon cancer associated with gravidity, which was attenuated in the analysis with parity. Increasing gravidity and parity were associated with a suggestion of a decreasing trend in risk for rectal cancer (p for trend = 0.07). Compared with women who had equal numbers of pregnancies and live births, women who were nulligravid and nulliparous had a 40%-60% increased risk of colon cancer. There was a suggestion of a reduced risk of both colon and rectal cancer associated with one more pregnancy than live birth. There was a suggestion of an increased risk of MSI-high tumors with nulligravidity and nulliparity.

CONCLUSIONS

These results confirm the importance of pregnancy events in the etiology of colon and rectal cancer.

Opposite association of serum prolactin and survival in patients with colon and rectal carcinomas: influence of preoperative radiotherapy

Prolactin (PRL) is a pleiotropic hormone associated with the progression of various cancers, including colorectal cancer (CRC). Here we investigate whether the association of serum PRL concentration and survival is affected by tumor location and preoperative radiotherapy (PRERT) in patients with CRC cancer. Serum PRL was determined in 82 CRC patients without previous treatment. Patients with PRL concentrations at and above the 75th percentile (high PRL) or below this level (low PRL), had a significant correlation with overall survival determined using the Kaplan-Meier method. In colon cancer, there was an increased risk of mortality when PRL values were at and above the highest quartile (22% vs. 73%; P = 0.01). In contrast, in rectal cancer, high PRL values were associated with a significant overall survival advantage (88% vs. 44%; P = 0.05), which became more significant (100% vs. 34%; P = 0.005) when only rectal cancer patients receiving PRERT were compared. These findings suggest that tumor location and adjuvant radiotherapy influence the association between circulating PRL and survival in CRC.