Distribution of Estrogen and Progesterone Receptors in Primary Tumor and Lymph Nodes in Individual Patients with Breast Cancer

Occult breast cancer may originate from ectopic breast tissue present in axillary lymph nodes

PURPOSE

Occult breast cancer (OBC) is classified as a carcinoma of unknown primary, and involves axillary lymphadenopathy and is histologically consistent with metastatic breast cancer. OBC has been conventionally considered as a metastatic lymph node lesion, the origin of which is an undetectable breast tumor. Therefore, OBC patients would usually have undergone axillary lymph node dissection, and mastectomy or whole breast radiotherapy (WBRT). However, majority of OBC reports have been based on cases that were diagnosed during a period when diagnostics was still relatively primitive, and when magnetic resonance imaging was not yet a standard preoperative assessment. Therefore, there have been many false negatives in the breast based on preoperative assessment.

METHODS

We herein hypothesize that the origin of OBC is ectopic breast tissue present in axillary lymph nodes (ALNs). If our hypothesis is true, mastectomy and WBRT may be unnecessary for OBC patients.

RESULTS

Our hypothesis is supported by several findings. First, advances in radiological imaging have suggested that a primary breast tumor is absent in OBC patients. Second, proliferative breast lesions arising from ectopic breast present in ALNs have been reported. Lastly, cellular subtypes in OBC based on immunohistochemistry are of various types including ordinary breast cancer and the prognosis is not worse than stage II breast cancer.

CONCLUSION

It is important to distinguish between "primary" OBC in ALNs and "metastatic" OBC from micro-primary breast tumor. Further studies are required to determine if omission of mastectomy and WBRT is acceptable.

Variations in Estrogen and Progesterone Receptor Content in Premenopausal Breast Cancer Patients Throughout the Menstrual Cycle

Estrogen (ER) and progesterone (PgR) receptor content was assayed in 290 premenopausal women with primary breast cancer, in order to investigate the influence of endogenous hormones on cytoplasmic receptor concentrations throughout the menstrual cycle, subdivided into four phases of ovarian function (early and late follicular phase, early and late luteal phase). Of the total population, 231 (79.7 %) patients were ER positive and 59 (20.3 %) were ER negative; 220 (75.9 %) were PgR positive and 70 (24.1 %) were PgR negative. The percentages of positive cases were almost constant in each phase. No significant difference in mean values of ER concentration was noted throughout the cycle. Instead, the PgR concentration significantly increased from the first to the third phase (P = 0.02) and decreased from the third to the fourth phase (P = 0.01). Our results suggest that ER- and PgR- cases are homogeneously distributed and not influenced by the phase of the cycle. Moreover, they suggest that PgR measurement in the luteal phase, rather than in other phases, prevents the occurrence of false low PgR levels and, at the same time, improves its prognostic significance and response rate to endocrine therapy.

Variability in hormone and growth factor receptor expression in primary versus recurrent, metastatic, and post-neoadjuvant breast carcinoma

The introduction of selective molecular targeted therapy, specifically tamoxifen and trastuzumab, has significantly altered the clinical behavior of breast carcinoma. Several questions remain, however, regarding potential phenotypic drifts in estrogen receptor (ER), progesterone receptor (PR), and epidermal growth factor receptor (Her-2/neu) expression between the primary and metastatic site. Whether patients should be tested for ER, PR, and Her-2/neu expression in the nodal or distant metastatic site, local recurrence and following neoadjuvant therapy, and whether this has an effect on prognosis remains elusive. A review of 45 studies addressing ER, PR, and Her-2/neu expression in lymph node metastasis, distant metastasis, local recurrence, and post-neoadjuvant therapy revealed the following average phenotypic drift in ER, PR, and Her-2/neu expression, respectively: 13.1 % (median = 10.0 %), 13.8 % (median = 16.0 %), and 7.7 % (median = 5.0 %) for lymph node metastasis; 21.8 % (median = 19.5 %), 30.8 % (median = 33.5 %), and 7.6 % (median = 6.1 %) for distant metastasis; 19.8 % (median = 13.4 %), 27.1 % (median = 28.6 %), and 6.6 % (median = 1.6 %) for local recurrence; and 12.9 % (median = 8.0 %), 32.0 % (median = 20.0 %), and 8.9 % (median = 0 %) post-neoadjuvant therapy. The above findings support the notion of re-evaluating ER, PR, and Her-2/neu expression in distant metastasis, lymph node metastasis and to a lesser extent local recurrence. The effects of neoadjuvant therapy on receptor expression are more pronounced for PR, which may have a prognostic role in therapy efficacy.

[Hormone receptors and HER-2 changes during breast cancer progression: clinical implications]

Breast cancer remains a major public health problem. Even if there is an increase in this cancer curability, metastatic breast cancer remains a lethal disease in the vast majority of cases. Therapeutic advances in the chemotherapeutic and targeted therapies fields induced an increase in survival, however the proportion of long survivors remains low. Phenotypic instability, an early process initiated during tumour progression, and continued on the metastatic stage of the disease, can be one of the putative hypotheses explaining these results. An increasing amount of scientific data are pledging for a reanalysis of the phenotypic profile regarding hormone receptors and HER-2 status of metastatic lesions in order to identify drugable targets and allow individualisation of the treatment of these metastatic breast cancer patients. Phenotypic changes between the primary tumour and the paired metastatic lymph nodes are a challenging pitfall, raising the question of which site has to be assessed in the adjuvant treatment decision process. This article presents a comprehensive analysis of the frequency of theses phenotypic changes altogether with new modalities to evaluate this phenotypic status.

A patient with occult breast cancer presenting with an axillary lymph node metastasis and a synchronous contralateral breast cancer

Detection of a breast mass accompanied by a contralateral axillary lymphadenopathy presents a dilemma because of the possible presence of an occult breast cancer on the same side as the axillary lymphadenopathy. A patient presented with an axillary lymphadenopathy from an occult breast cancer and a synchronous contralateral breast cancer, for which the differential diagnosis was established through a significant difference in estrogen and progesterone receptor levels. The patient was treated with neoadjuvant chemotherapy followed by bilateral modified radical mastectomy, adjuvant chemotherapy, and adjuvant radiation therapy. She is alive and free of disease 1.5 years after the diagnosis.

Estrogen and progesterone receptor content in bilateral breast cancer

Estrogen and progesterone receptor content was determined in 34 patients with synchronous and 23 patients with asynchronous bilateral breast cancer. Steroid receptor content was measured quantitatively by DCC method. It was shown that progesterone receptor content could not be predicted, as well as, that steroid receptor content of the second tumor significantly influenced the development of asynchronous bilateral breast cancer. The high discordance rate concerning histologic type between two tumors within synchronous as well as asynchronous biopsies was observed. The obtained results indicate that both synchronous and asynchronous bilateral breast tumors may be considered as biologically different tumors whose both steroid receptor levels should be determined whenever possible.

Variations in the content of steroid receptors in breast cancer. Comparison between primary tumors and metastatic lesions

Steroid receptors were determined by the dextran-coated charcoal method in 193 breast cancer patients in different clinical stages of disease. Quantitative estrogen and progesterone values in primary tumors (n = 69) were compared with receptors in regional lymph node metastases (n = 28) and in distant malignant deposits (n = 65). The groups including receptor values from primaries and regional lymph node metastases (n = 15) and from primaries and distant metastatic lesions (n = 16) in the same patients were also analyzed. The obtained results indicated relative stability of both receptors in loco-regional disease, but with a tendency towards lower receptor values in lesions from advanced disease. This tendency is probably caused by the disease progression itself, but the influence of radio- or chemotherapy cannot be excluded.

Oestrogen and progesterone receptor status in bone biopsy specimens from patients with breast cancer

Of 16 breast cancer patients with histologically proven, tumour-infiltrating biopsy specimens most had low ER and PR values; the ER and PR contents varied between 0 and 135 and 0 and 44 fmol/mg protein, respectively. With the conventional clinical threshold of 10 fmol/mg protein, 8 specimens (50%) were ER-PR-, 4 (25%) ER-PR+, 3 (19%) ER+PR+ and 1 (6%) ER+PR-. ER levels were significantly lower in the tumoral bone lesion compared with the primary tumour. For 15 patients with negative biopsies and without endocrine treatment, ER and PR concentrations were quantifiable (2 fmol/mg protein or more) in 9 (60%) and 11 cases (73%), respectively. 8 of 9 patients over 55 (89%) were ER+ (2 fmol/mg protein or more). Conversely, for patients under 55, 1 of 6 (17%) was ER+ (P less than 0.001). Results for PR were similar. These data strongly suggest that steroid receptors are present in healthy bone tissue.

Progesterone receptor determination in human breast tumors by immunocytochemical and biochemical techniques

Progesterone receptors were determined on frozen sections from 74 primary human breast tumors by an immunocytochemical assay using an indirect avidin-biotin peroxidase method. In the same tumors, cytosol estrogen (ERc) and progesterone receptors (PgRc) were determined by ligand binding assay, and nuclear estrogen (ERn) and progesterone receptors (PgRn) were determined by an immunoassay. Immunocytochemical staining was seen in 36% of tumors. It was predominantly nuclear and there was extensive cell to cell heterogeneity. When the immunocytochemical results were compared to PgRc the agreement rate was 63%, but it was 77% when compared to PgRn. About one third (38%) of PgRc positive tumors were immunocytochemically defined as negative. Thus a significant discordance exists between this immunocytochemical assay for PgR and both the conventional radioligand assay (used for PgRc) and the relatively new enzyme immunoassay (used for PgRn). However discordance rates were critically influenced by the arbitrary cutoff levels that were used to define receptor positivity in the biochemical assays. Our studies support the addition to, rather than the substitution of, immunocytochemical methods, to the conventional biochemical assays for PgR, until long-term follow-up studies of patients with PgRn and immunocytochemical PgR determinations become available.

Modern thoughts on lymph nodes in breast cancer

Axillary lymph node status remains the single most useful prognostic parameter in breast cancer patients. As clinical examination, imaging techniques, and lymph node sampling methods cannot accurately assess the axillary node involvement, a complete axillary dissection should always be performed. Moreover, this technique provides an excellent treatment modality for regional disease, abolishing the need for radiotherapy to the axilla. The status of the internal mammary lymph nodes is of less importance in the management of the breast cancer patient.

Heterogeneity of soluble and nuclear oestrogen receptor status of involved nodes in relation to primary breast cancer

Both soluble and nuclear oestrogen receptors were measured in at least two different portions of primary breast cancer and in concurrent metastatic tissue from axillary nodes. Oestrogen receptor (ER) status of involved nodes was found highly consistent with that of primary tumours. Of the 67 patients studied, 30 had metastatic nodes which contained both soluble and nuclear ER. Of these, 27 were associated with a primary cancer which also had both soluble and nuclear ER, determined in at least two separate parts of the primary cancer. Conversely, none of the completely negative primaries gave rise to fully receptor positive metastatic tissue. Surprisingly, 17 out of 20 heterogeneous primary tumours, i.e. those containing both receptor positive and negative components, generated receptor negative metastatic nodes. Moreover, in 7 of the 8 patients with N-2 stage nodal involvement, the metastatic disease had arisen from primaries which were either completely receptor negative or with a heterogeneous ER status. It is suggested that macroscopic heterogeneity of ER status in primary breast cancer is associated with poor prognosis.