The activation of the phosphatidylinositol 3 kinase (PI3K)-Akt pathway is a known causal mechanism of oncogenesis and resistance to cancer treatments. The process of PI3K-Akt pathway activation is complex and includes receptor tyrosine kinase(RTK) activation, PIK3CA mutations, loss of phosphatase and tensin homolog (PTEN), Akt mutations, tuberous sclerosis complex (TSC) mutations, and Ras homologue enriched in brain (RHEB) gene amplifications. The blockage of mammalian target of rapamycin (mTOR), the key downstream pathway protein, has been successful in selected cancer types, with mTOR-targeting agents available for clinical use. Other novel drugs blocking this pathway such as PI3K inhibitors, Akt inhibitors and PDK-1 inhibitors are currently only available for investigational use, but have shown promise as cancer therapies in both preclinical and early phase clinical studies. The newer generations of these inhibitors are more specific and have improved potency and safety. The combinations of targeted treatments against this pathway, blocking multiple different steps, are under preliminary investigation. Further research is needed to identify the biomarkers that predict treatment response and resistance in order to optimize personalized medicine.

Introduction/Background. Nonmetastatic castrate resistant prostate cancer (CRPC) is a challenging disease state. The objective of this study was to evaluate the efficacy and tolerability of bevacizumab in nonmetastatic CRPC patients. Patients. Patients with prostate cancer who developed PSA recurrence after local therapy were included if they had absence of bone or visceral metastases and PSA progression despite androgen deprivation therapy. Methods. Bevacizumab 10 mg/kg intravenously was administered every 14 days until PSA progression, development of metastasis, or unacceptable toxicity. Results. 15 patients were enrolled and treated with bevacizumab for a median duration of 3.1 months. Median baseline PSA was 27 ng/mL, and seven patients had Gleason Score ≥8. Five patients had declined in PSA during the treatment. Median PSA doubling time was prolonged from 4.7 months pretreatment to 6.5 months. Median time to PSA progression and new metastasis were 2.8 and 7.9 months, respectively. There were three grade 3 adverse events (one proteinuria and two hypertension) and one pulmonary embolism. There was no treatment-related mortality. Conclusion. Bevacizumab therapy had minimal impact on the disease course of nonmetastatic CRPC, and investigation of novel strategies is needed.

Paraneoplastic cerebellar degeneration (PCD) is a rare paraneoplastic syndrome, occurring in <1% of breast cancers. We describe a 32-year-old female presenting with ataxia subsequently diagnosed with poorly differentiated breast cancer. She was serum anti-Yo antibody positive, with estrogen/progesterone receptor negative and HER2/neu receptor positive breast cancer. Neurological symptoms progressed despite modified radical mastectomy, supraclavicular lymphadenectomy, intravenous immunoglobulin, corticosteroids, transtuzumab, and combination chemotherapy. We performed a literature search, which found a possible association between anti-Yo positive PCD and HER2/neu-expressing breast cancer.