INS and breast cancer: However, one study by Liefvendahl et al. found that glargine had little to no increased mitogenic effect in malignant cell lines for breast cancer (MCF-7 and SKBR-3) or osteosarcoma (SaOS-2) compared to human insulin [93], The caveat in this controversy may relate to a dose-time exposure to insulin treatment, particularly with glargine; that is, cumulative insulin intake over time may potentially increase the cancer risk and mortality [98].