Poly-ADP-ribose polymerase inhibitors (PARPis) are the most active and interesting therapies approved for the treatment of epithelial ovarian cancer. They have changed the clinical management of a disease characterized, in almost half of cases, by extreme genetic complexity and alteration of DNA damage repair pathways, particularly homologous recombination (HR) deficiency. In this review, we provide an updated overview of the available results of recent clinical trials on the three Food and Drug Administration and European Medicines Agency approved PARPis in ovarian cancer: olaparib, niraparib, and rucaparib. Furthermore, we anticipate the future perspective of combination regimens with antiangiogenic, immunocheckpoint inhibitors, and other biological agents as strategies to overcome resistance mechanisms, potentiate the therapeutic efficacy, and expand their clinical use in non-HR deficient tumors. Mechanism of action of PARPs and PARPs inhibitors PARPs are a family of 17 nucleoproteins characterized by a common catalytic site that transfers an ADP-ribose group on a specific acceptor protein using NAD + as cofactor. Interestingly, most PARP members are able to transfer only a mono-ADP ribose group to their target proteins, whereas PARP1, PARP2, PARP3, PARP5a, PARP5b characteristically add repeated ADP-ribose units, thus generating long poly(ADP-ribose) (PAR) chains [5]. This post-translational protein modification is named PARylation and allows PARPs involvement in different cellular activities. In this regard, PARP1 is the best characterized PARP. PARP1 modulates chromatine structure via PARylation of core histone proteins resulting in chromatine relaxation, thus enabling replication, repair, and transcription processes [6]. As to transcription, PARP1 plays a pivotal role in its regulation by both serving as a transcriptional cofactor and by hindering methylation of specific sequences, like those of housekeeping genes (Fig. 1a/b). To date, activation of PARP-1, dependent on CCCTC binding factor (CTCF), appears to affect DNA

Over the past decade, the advent of gene expression micro-array technology has led to the identification of different actionable targets including various genomic alterations, androgen receptor, PARP, PI3K, VEGF and other proteins of the angiogenic pathway. Thus, novel targeted drugs have been tested in clinical trials reporting promising results in specific TNBC molecular subgroups. Although cytotoxic chemotherapy remains the mainstay of treatment for TNBC patients, the identification of novel 'drugable' targets and pathways for developing personalized treatments represents a promising investigational approach in the management of the TNBC subtype.

Triple negative breast cancers (TNBCs) are characterized by worse prognosis, higher propensity to earlier metastases, and shorter survival after recurrence compared with other breast cancer subtypes. Anthracycline- and taxane-based chemotherapy is still the mainstay of treatment in early stages, although several escalation approaches have been evaluated to improve survival outcomes. The addition of platinum salts to standard neoadjuvant chemotherapy (NACT) remains controversial due to the lack of clear survival advantage, and the use of adjuvant capecitabine represents a valid treatment option in TNBC patients with residual disease after NACT. Recently, several clinical trials showed promising results through the use of poly ADP-ribose polymerase (PARP) inhibitors and by incorporating immunotherapy with chemotherapy, enriching treatment options beyond conventional cytotoxic agents. In this review, we provided an overview on the current standard of care and a comprehensive update of the recent advances in the management of early stage TNBC and focused on the latest emerging biomarkers and their clinical application to select the best therapeutic strategy in this hard-to-treat population.

Opinion statementAbout 70–80% of early breast cancer (BC) patients receive adjuvant endocrine therapy (ET) for at least 5 years. ET includes in the majority of cases the use of aromatase inhibitors, as upfront or switch strategy, that lead to impaired bone health. Given the high incidence and also the high prevalence of BC, cancer treatment–induced bone loss (CTIBL) represents the most common long-term adverse event experimented by patients with hormone receptor positive tumours. CTIBL is responsible for osteoporosis occurrence and, as a consequence, fragility fractures that may negatively affect quality of life and survival expectancy. As recommended by main international guidelines, BC women on aromatase inhibitors should be carefully assessed for their fracture risk at baseline and periodically reassessed during adjuvant ET in order to early detect significant worsening in terms of bone health. Antiresorptive agents, together with adequate intake of calcium and vitamin D, should be administered in BC patients during all course of ET, especially in those at high risk of osteoporotic fractures, as calculated by tools available for clinicians. Bisphosphonates, such as zoledronate or pamidronate, and anti-RANKL antibody, denosumab, are the two classes of antiresorptive drugs used in clinical practice with similar efficacy in preventing bone loss induced by aromatase inhibitor therapy. The choice between them, in the absence of direct comparison, should be based on patients’ preference and compliance; the different safety profile is mainly related to the route of administration, although both types of drugs are manageable with due care, since most of the adverse events are predictable and preventable. Despite advances in management of CTIBL, several issues such as the optimal time of starting antiresorptive agents and the duration of treatment remain unanswered. Future clinical trials as well as increased awareness of bone health are needed to improve prevention, assessment and treatment of CTIBL in these long-term survivor patients.

BackgroundThe emerging role of next-generation sequencing (NGS) targeted panels is revolutionising our approach to cancer patients, providing information on gene alterations helpful for diagnosis and clinical decision, in a short time and with acceptable costs.Materials and methodsIn this work, we evaluated the clinical application of FoundationOne CDx test, a hybrid capture-based NGS. This test identifies alterations in 324 genes, tumour mutational burden and genomic signatures as microsatellite instability. The decision to obtain the NGS assay for a particular patient was done according to investigator’s choice.ResultsOverall, 122 tumour specimens were analysed, of which 84 (68.85%) succeeded. The success rate was influenced by type of specimen formalin-fixed paraffin embedded (FFPE block vs FFPE slides), by origin of the sample (surgery vs biopsy) and by time of fixation (<5 years vs ≥5 years). The most frequent subgroups of effective reports derived from colorectal cancer (25 samples), non-small-cell lung cancer (16 samples), ovarian cancer (10 samples), biliary tract cancer (9 samples), breast cancer (7 samples), gastric cancer (7 samples). The most frequent alterations found in whole population referred to TP53 (45.9%), KRAS (19.6%) and APC (13.9%). Furthermore, we performed an analysis of patients in whom this comprehensive genomic profiling (CGP) had a relevance for the patient’s disease.ConclusionsOn our opinion, CGP could be proposed in clinical practice in order to select patients that could most benefit from the analysis proposed, like patients with good performance status without any available treatments or with unexpected resistance to a therapy.