Receptors for epidermal growth factor and sex steroid hormones in human colorectal carcinomas

Iodinated epidermal growth factor was used to identify its specific receptor in 32 human colorectal carcinomas. The receptor was found in 25% of the tumors with values between 6.9 - 104.0 fmoles/mg DNA. Receptors for estrogen and progesterone were detected in 45 and 25% of the tumors respectively. No correlation was observed between short term survival and content of receptors for sex steroid hormones. Four of the 8 patients with detectable levels of epidermal growth factor receptor had experienced relapse.

Transforming growth factor alpha in human mammary carcinomas and their metastases

A binding competition assay was used to measure the content of transforming growth factor alpha in human mammary carcinomas and their metastases. Thirty one percent of the primary and 50 percent of the metastases expressed the transforming growth factor alpha with values ranging between 1.6 to 278 EGF equivalent ng/mg tumour extract protein. There was no correlation between the transforming growth factor alpha content and the estrogen receptor value.

Identification of transforming growth factor alpha in human primary breast carcinomas

Primary human mammary carcinomas were found to contain an acid stable polypeptide which bound to the receptor for epidermal growth factor (EGF). This polypeptide which was antigenetically different from EGF and thus identified as Tumor Growth Factor (TGF) alpha, could be identified in 25% of the tumors. Among these tumors 40% contained measurable levels of the EGF receptor. Thus these tumors exhibit the molecular prerequisite for autocrine growth stimulation.

Prognostic significance of the receptor for epidermal growth factor in human mammary carcinomas

125I-EGF binding technique was used to demonstrate high affinity receptor binding for epidermal growth factor (EGF-R) in 72 human mammary carcinomas. 27% of the tumors were EGF-R positive and the presence of this receptor was correlated with receptor levels for estradiol, DNA-pattern, proliferative index, thymidine kinase, tumor size, number of lymph node metastases and 6-year relapse probability. Our results confirm previous reports of an inverse relation between the cellular content of EGF-R and ER. In addition, we could associate EGF-R positivity with an aneuploid DNA-pattern and an increased growth rate, as measured by proliferative index. No correlation was found between EGF-R positivity in the primary tumor and presence of axillary lymph node metastasis at the time of operation. The 6-year relapse rate was somewhat higher for patients whose primary tumors were EGF-R positive. Moreover patients who had lymph node metastases at the time of operation and EGF-R positive tumors experienced a significantly lower 6-year disease free survival rate as compared to those who were node negative and had receptor negative tumors. It remains to be shown whether EGF-R alone can be used as an independent prognostic factor.

Receptors for EGF and oestradiol and thymidinekinase activity in different histological subgroups of human mammary carcinomas

The cellular content of receptors for epidermal growth factor (EGF) was measured in different histological subgroups of human mammary carcinomas. EGF receptors were detected in 36% of the ductal and all the medullary carcinomas. In contrast lobular and pure colloid tumours did not contain measurable amounts of the receptor. The receptor was found both among tumours with an euploid and aneuploid DNA pattern. The EGF receptor is thus found in carcinomas with a varying degree of differentiation as judged by the cellular DNA pattern. There was no correlation between the proliferative activity of the tumours as measured by thymidinekinase activity and the amount of EGF receptors in the tumour. Tumours with detectable EGF receptor often had low levels of oestrogen receptor. This finding could only partly be explained by the menstrual status of the patients.

Receptors for epidermal growth factor in human mammary carcinomas and their metastases

The tumor cell content of the receptor for epidermal growth factor (EGF-R) and estrogen receptor (ER) was analyzed in 36 primary breast carcinomas and their metastatic deposits. Twenty-five percent of the primary tumors and 48 percent of the metastases exhibited measurable levels of the receptor. The frequency of EGF-R positivity was the same for cutaneous and lymph node recurrences. No discrepancy was observed with respect to ER content between primary tumors and their metastases.