Plasma and tissue prolactin detection in colon carcinoma

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.

Effects of blood collection conditions on ovarian cancer serum markers

BACKGROUND

Evaluating diagnostic and early detection biomarkers requires comparing serum protein concentrations among biosamples ascertained from subjects with and without cancer. Efforts are generally made to standardize blood processing and storage conditions for cases and controls, but blood sample collection conditions cannot be completely controlled. For example, blood samples from cases are often obtained from persons aware of their diagnoses, and collected after fasting or in surgery, whereas blood samples from some controls may be obtained in different conditions, such as a clinic visit. By measuring the effects of differences in collection conditions on three different markers, we investigated the potential of these effects to bias validation studies.

METHODOLOGY AND PRINCIPLE FINDINGS

We analyzed serum concentrations of three previously studied putative ovarian cancer serum biomarkers-CA 125, Prolactin and MIF-in healthy women, women with ovarian cancer undergoing gynecologic surgery, women undergoing surgery for benign ovary pathology, and women undergoing surgery with pathologically normal ovaries. For women undergoing surgery, a blood sample was collected either in the clinic 1 to 39 days prior to surgery, or on the day of surgery after anesthesia was administered but prior to the surgical procedure, or both. We found that one marker, prolactin, was dramatically affected by collection conditions, while CA 125 and MIF were unaffected. Prolactin levels were not different between case and control groups after accounting for the conditions of sample collection, suggesting that sample ascertainment could explain some or all of the previously reported results about its potential as a biomarker for ovarian cancer.

CONCLUSIONS

Biomarker validation studies should use standardized collection conditions, use multiple control groups, and/or collect samples from cases prior to influence of diagnosis whenever feasible to detect and correct for potential biases associated with sample collection.

Plasma prolactin in patients with colorectal cancer

BACKGROUND

Colorectal cancer is a common malignancy of the gastrointestinal tract. It is the second cancer cause of death in females and third in males. Production of prolactin has been reported with several tumours. However, elevated prolactin plasma levels in colorectal cancer patients remained unclear.

METHODS

In this cross sectional study serum prolactin and carcinoembryonic antigen (CEA) concentrations were assayed using immunoradiometric assay kits, preoperatively in 47 patients, and the results were compared with 51 age and sex matched controls.

RESULTS

Prolactin and CEA concentration in patients were significantly more as compared with controls. Hyperprolactinemia was found in 36 (76.6%) patients, while 28 (59.6%) had high level of CEA.

CONCLUSIONS

Prolactin may be a better tumour marker than CEA in patients with colorectal malignancy.