Neoadjuvant chemotherapy for locally advanced breast cancer results in alterations in preoperative tumor marker status

Neoadjuvant therapy followed by breast-conserving surgery has become an acceptable option for patients with locally advanced breast cancer. Although a distinct survival benefit has not been demonstrated using this approach, several questions have been raised following such therapy including its effects on receptor status and tumor markers. The current study retrospectively reviews estrogen receptor (ER), progesterone receptor (PR), and HER2-neu status in 55 consecutive patients treated by neoadjuvant chemotherapy. Preoperative and postoperative tumor markers were available for 43 of the 55 patients (78%). The pathologic complete tumor response rate (pCR) for this group was 19 per cent (8/43). Of those patients who did not achieve a pCR (n = 35), a change in tumor markers was seen in 25.7 per cent (9/35) of patients. When compared to a control group not undergoing neoadjuvant therapy, a significantly higher percent change in marker expression was noted in the neoadjuvant group (25.7% vs 5.9%, P = 0.046). ER, PR, and HER2-neu status remain important prognostic indicators for breast cancer. Tumor markers are useful in planning adjuvant therapy regimens. In this review, nearly 19 per cent of patients achieved a pCR. In patients not achieving a pCR, one in four patients had at least one change in tumor marker status. This study demonstrates the importance of establishing receptor and marker status prior to neoadjuvant therapy, as many patients will achieve a pCR and make tumor analysis impossible. Postoperative marker studies should be performed given the possibility of a change in status. The clinical relevance of this data will require further long-term follow-up. Until such data becomes available, caution should be considered when basing adjuvant therapy regimens on preoperative tumor marker studies alone.

Accurate axillary nodal staging can be achieved after neoadjuvant therapy for locally advanced breast cancer

Lymph node status remains the most important prognostic indicator for breast cancer. Recent reports have established that the accuracy of assessing lymph node status is proportional to the number of nodes dissected. The accuracy of axillary staging following neoadjuvant chemotherapy has been cited as a technical concern due to limited node retrieval. The current study attempts to evaluate the ability to perform sentinel node biopsy (SNB) and formal axillary node dissection (AND) following neoadjuvant chemotherapy and to compare these results with non-neoadjuvant patients. One hundred sixteen consecutive patients undergoing SNB with simultaneous AND were retrospectively reviewed. Forty-two of these patients were treated with neoadjuvant chemotherapy prior to AND. Overall success rate in performing SNB in the neoadjuvant group was 95 per cent, and no false negatives have been noted to date. The overall SNB success rate in the non-neoadjuvant group was also 95 per cent with a false negative rate of 3 per cent. After AND in each group, a mean of 21 nodes were retrieved in the neoadjuvant group and 17.9 nodes in the non-neoadjuvant group (P = 0.018). In the neoadjuvant group, there were 19 node positive patients (42%) and 21 patients (28%) in the non-neoadjuvant group (P = 0.16). The mean number of positive nodes per patient was also similar between the two groups (2.9 in the neoadjuvant group vs 1.67 in the non-neoadjuvant group, P = 0.10). Following neoadjuvant therapy, accurate evaluation of the axilla is feasible. In this study, the mean number of nodes is significantly different in favor of the neoadjuvant group, but there is no significant difference in the number of node positive patients identified or in the mean number of positive nodes identified per patient. SNB is technically feasible with accuracy similar to that seen in patients with no history of neoadjuvant therapy. Neoadjuvant chemotherapy extends the use of breast-conserving therapy without sacrificing the ability to accurately stage the axilla either by use of standard axillary dissection or SNB.

Low-dose vasopressin in the treatment of vasodilatory septic shock

BACKGROUND

Despite appropriate therapy, refractory hypotension often occurs in septic shock. A double-blinded placebo controlled clinical trial was performed to assess the role of low-dose vasopressin (VP) as a pressor agent in septic shock.

METHODS

Patients admitted to a trauma intensive care unit with vasodilatory septic shock were randomized to receive either VP at 0.04 U/min (n = 5) or placebo (n = 5). Vasodilatory septic shock was defined as a need for catecholamine agents to maintain a mean arterial pressure more than or equal to 70 mm Hg, despite a cardiac index more than 2.5 L/min and a minimal pulmonary artery wedge pressure more than 12 mm Hg. After 1 hour of initiation of the study drug, attempts to discontinue norepinephrine, phenylephrine, and/or dopamine, in respective order, were undertaken provided that the mean arterial pressure remained more than or equal to 70 mm Hg.

RESULTS

A vasopressin infusion increased systolic arterial pressure (98 +/- 5 to 125 +/- 8 mm Hg, p < 0.008) because of peripheral vasoconstriction (systemic vascular resistance increased from 878 +/- 218 to 1,190 +/- 213 dynes/s per cm(-5) p < 0.05). Arterial pressure and systemic vascular resistance were statistically unaffected in the placebo group. Before study termination, measured at 24 hours after drug initiation, two patients in the placebo group died of refractory hypotension. However, all patients receiving VP survived the 24-hour study period and had all other catecholamine pressors withdrawn and blood pressure maintained solely with a low-dose VP infusion.

CONCLUSION

A VP infusion improved arterial pressure and permitted the withdrawal of catecholamine vasopressors. VP is a useful agent in the treatment of refractory septic shock.