Reduced tumor cell transfer with contact neodymium-yttrium-aluminium garnett laser scalpels

Response of the Urothelial Carcinoma Cell Lines to Cisplatin

Cisplatin (CDDP)-based chemotherapy is the standard of care in patients with muscle-invasive bladder cancer. However, in a large number of cases, the disease becomes resistant or does not respond to CDDP, and thus progresses and disseminates. In such cases, prognosis of patients is very poor. CDDP manifests its cytotoxic effects mainly through DNA damage induction. Hence, response to CDDP is mainly dependent on DNA damage repair and tolerance mechanisms. Herein, we have examined CDDP response in a panel of the urothelial carcinoma cell (UCC) lines. We characterized these cell lines with regard to viability after CDDP treatment, as well as kinetics of induction and repair of CDDP-induced DNA damage. We demonstrate that repair of CDDP-induced DNA lesions correlates, at least to some extent, with CDDP sensitivity. Furthermore, we monitored expression of the key genes involved in selected DNA repair and tolerance mechanisms, nucleotide excision repair, homologous recombination and translesion DNA synthesis, and show that it differs in the UCC lines and positively correlates with CDDP resistance. Our data indicate that CDDP response in the UCC lines is dependent on DNA damage repair and tolerance factors, which may, therefore, represent valuable therapeutic targets in this malignancy.

Reduced in vivo local recurrence with contact neodymium: Yttrium-Aluminium-Garnet (Nd:YAG) laser scalpels

BACKGROUND AND OBJECTIVE

Local recurrence after surgical resection for breast cancer is a significant problem and is often not controlled by radiation or chemotherapy treatments. Local recurrence is thought to be, at least in part, due to residual disease, and/or due to the contamination of the surgical field during resection. STUDY DESIGN MATERIALS AND METHODS: To address this later concern, we defined a model system using the mouse mammary cell line, EMT6. Using this model system, we have directly compared the rate of local recurrence of two different surgical approaches. One approach employed the use of traditional surgical instruments, and the other used a comparatively new contact Nd:YAG laser system. Tumor-bearing animals (242) were randomized into three groups. One group consisted of 50 animals that were not treated; 103 animals were randomized into a treatment group that received surgical resection using traditional instruments; 89 animals were resected using the contact laser system. In both surgical procedures, an intentional incision was made through the tumor and then through an uninvolved portion of the surgical field in an attempt to "seed" the incision using the contaminated surgical instrument.

RESULTS

Twenty-one of the 103 scalpel-treated animals had local recurrence; only seven of the 89 laser-treated animal had local recurrence. The untreated group died of disease within 8 weeks. In the treatment groups, recurrences were palpable within 1 week. At the time of death for all groups, no metastatic lesions were noted.

CONCLUSION

These findings support the conclusions that the EMT6 cell line is a useful model to study local recurrence and that contact laser surgery provides about a 50% improvement in the control of local disease in vivo (P < 0.05).