A comparison of robotic and laparoscopic minimally invasive adrenalectomy for adrenal malignancies

BACKGROUND

Although guidelines recommend open adrenalectomy for most resectable adrenal malignancies, minimally invasive adrenalectomies are performed. Robotic adrenalectomies have become more popular recently, but there is a paucity of literature comparing laparoscopic and robotic resections.

METHODS

Patients who underwent a planned minimally invasive adrenalectomy for adrenal malignancies (adrenocortical carcinoma, malignant pheochromocytoma, other carcinoma) were identified in the National Cancer Database. The primary outcome was the conversion rate from minimally invasive to open. Other post-operative outcomes and survival were compared.

RESULTS

416 patients (76.5%) underwent a laparoscopic adrenalectomy and 128 (23.5%) underwent a robotic operation. Demographics and clinical characteristics were similar. Approximately 19% of tumors resected by a minimally invasive approach were > 10 cm. The intra-operative conversion rate was decreased among robotic adrenalectomies relative to laparoscopic on univariate (7.8% vs. 18.3%, p = 0.005) and multivariable (odds ratio 0.39, p = 0.01) analyses. Using marginal standardization, there was a stepwise increase in the conversion rate as tumor size increased (< 5, 5-10, > 10 cm) for laparoscopic (7.5%, 18.0%, 33.2%) and robotic (3.1%, 8.3%, 17.3%) adrenalectomies. Operations which required conversion had a greater margin positivity rate, greater length of stay, and an association with poor overall survival.

CONCLUSION

In contrast to most clinical guidelines, minimally invasive adrenalectomies are being performed on large malignant tumors. A laparoscopic approach was associated with a greater conversion rate and subsequent poor outcomes. If a surgeon is not planning an open adrenalectomy, but adrenal malignancy is a possibility, robotic adrenalectomy may be the preferred approach for resectable adrenal tumors.

Abstract 347: Developing a novel immunotoxin that targets cells overexpressing ErbB2

Immunotoxins are chimeric proteins comprising a specific cellular targeting domain linked to a cytotoxic factor. Here we describe the design and use of a novel, peptide-based immunotoxin that can initiate selective cytotoxicity on ErbB2-positive cells. ErbB2 is a receptor tyrosine kinase that is overexpressed in the tumor cells of approximately 30% of breast cancer patients. Immunotoxin candidates were designed to incorporate a targeting ligand with affinity for ErbB2 along with a membrane lysin-based toxin domain. The use of a membrane lysin as the toxin domain distinguishes our immunotoxins from numerous others in that internalization of the toxin is not required to induce cell death. One particular peptide candidate, NL1.1-PSA, demonstrated selective cytotoxicity towards ErbB2-overexpressing cell lines. We utilized a bioengineering strategy to show that recombinant NL1.1-PSA immunotoxin expression by Escherichia coli also conferred selective cytotoxicity towards ErbB2-overexpressing cells. Our findings hold significant promise for the use of effective immunotoxins in cancer therapeutics. While Herceptin treatment has been effective in patients with ErbB2 positive breast cancer, our novel immunotoxin may ultimately prove to be a novel and efficacious addition to the arsenal of approaches used to eliminate Herceptin-resistant breast cancer cells.

Citation Format: Luqun Shen, Kelsey Weigel, Clayton Thomas, Lauren Drapalik, Zachary T. Schafer, Shaun Lee. Developing a novel immunotoxin that targets cells overexpressing ErbB2. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 347.

Design and evaluation of a peptide-based immunotoxin for breast cancer therapeutics

Immunotoxins are chimeric proteins comprising a specific cellular targeting domain linked to a cytotoxic factor. Here we describe the design and use of a novel, peptide-based immunotoxin that can initiate selective cytotoxicity on ErbB2-positive cells. ErbB2 is a receptor tyrosine kinase that is overexpressed in the tumor cells of approximately 30% of breast cancer patients. Immunotoxin candidates were designed to incorporate a targeting ligand with affinity for ErbB2 along with a membrane lysin-based toxin domain. One particular peptide candidate, NL1.1-PSA, demonstrated selective cytotoxicity towards ErbB2-overexpressing cell lines. We utilized a bioengineering strategy to show that recombinant NL1.1-PSA immunotoxin expression by Escherichia coli also conferred selective cytotoxicity towards ErbB2-overexpressing cells. Our findings hold significant promise for the use of effective immunotoxins in cancer therapeutics.