Risks and benefits of sentinel lymph node evaluation in the management of endometrial intraepithelial neoplasia.

INTRODUCTION: Endometroid intraepithelial neoplasia (EIN) is a premalignant lesion to endometrial cancer. Increasing number of gynecologic oncologists are performing sentinel lymph node (SLN) evaluation during hysterectomy for EIN to ensure complete staging if there is cancer on the final specimen. However, there are no clear guidelines and the benefits and risks to performing SLN evaluation for EIN patients are unclear. AREAS COVERED: This narrative review examines the advantages and disadvantages of SLN evaluation for EIN patients and provides an algorithm to assist clinicians in selectively applying the procedure for maximal patient benefit. Relevant articles up to March 2024 were obtained from a PubMed search on SLN use with endometrial pathology. EXPERT OPINION: Sentinel lymph node evaluation for patients with EIN is safe, feasible, and particularly important for the approximately 10% of patients with high-risk endometrial carcinoma on final pathology. However, as most diagnosed carcinomas are low-risk, SLN evaluation would have limited oncologic benefit. While SLN assessment may overtreat most patients with EIN, a significant minority of patients will be improperly staged. We propose an algorithm highlighting the importance of maximal preoperative endometrial sampling and stratifying patients via risk factors to selectively identify those who would benefit most from SLN evaluation.

Endometroid intraepithelial neoplasia (EIN) is a premalignant lesion to endometrial cancer, the most common gynecologic cancer in the United States. The definitive treatment for EIN is hysterectomy. An increasing number of gynecologic oncologists are performing sentinel lymph node (SLN) assessment during surgery for EIN since 30­40% of patients with EIN will have underlying carcinoma. For those patients, lymph node evaluation is important for cancer staging, especially if high-risk or advanced stage disease is found on the pathologic specimen. The SLN procedure cannot be performed post-hysterectomy, so an improperly staged patient may require a second operation for lymphadenectomy; this has a greater chance of morbidity compared to an SLN biopsy. However, an SLN evaluation still confers perioperative risk and comes at an additional monetary cost, especially when most patients diagnosed with endometrial cancer after EIN will ultimately have low-risk, stage IA disease. We propose an algorithm for clinicians to help determine which patients with EIN would best benefit from the SLN procedure; this includes maximizing preoperative endometrial sampling and considering selective criterion with risk factors for concurrent endometrial carcinoma including age, endometrial thickness, obesity, and molecular classification.

Resurgence of colistin: a review of resistance, toxicity, pharmacodynamics, and dosing.

Colistin is a polymyxin antibiotic that was discovered in the late 1940s for the treatment of gram-negative infections. After several years of clinical use, its popularity diminished because of reports of significant nephrotoxicity and neurotoxicity. Recently, the antibiotic has resurfaced as a last-line treatment option for multidrug-resistant organisms such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae. The need for antibiotics with coverage of these gram-negative pathogens is critical because of their high morbidity and mortality, making colistin a very important treatment option. Unfortunately, however, resistance to colistin has been documented among all three of these organisms in case reports. Although the exact mechanism causing colistin resistance has not been defined, it is hypothesized that the PmrA-PmrB and PhoP-PhoQ genetic regulatory systems may play a role. Colistin dosages must be optimized, as colistin is a last-line treatment option; in addition, suboptimal doses have been linked to the development of resistance. The lack of pharmacokinetic and pharmacodynamic studies and no universal harmonization of dose units, however, have made it difficult to derive optimal dosing regimens and specific dosing guidelines for colistin. In critically ill patients who may have multiorgan failure, renal insufficiency may alter colistin pharmacokinetics. Therefore, dosage alterations in this patient population are imperative to achieve maximal efficacy and minimal toxicity. With regard to colistin toxicity, most studies show that nephrotoxicity is reversible and less frequent than once thought, and neurotoxicity is rare. Further research is needed to fully understand the impact that the two regulatory systems have on resistance, as well as the dosages of colistin needed to inhibit and overcome these developing patterns.