Cyclin-dependent kinase 4/6 inhibitors in the treatment of advanced or metastatic breast cancer

OBJECTIVE

Despite the relatively high cure rates in early-stage breast cancer, advanced and metastatic breast cancer cases are associated with more inauspicious patient outcomes. Fortunately, with the advent of cyclin-dependent kinase (CDK)4/6 inhibitors (e.g. palbociclib, ribociclib, and abemaciclib) with endocrine therapy, survival in advanced and metastatic breast cancer has appreciably improved. In the current review, we discuss these distinctions and the concomitant implications associated with the individual CDK4/6 inhibitors.

DATA SOURCES

We conducted an extensive PubMed search comprising several review articles on the topic of advanced or metastatic breast cancer treatment, with specific terms that included CDK4/6 inhibitors, treatment, and breast cancer.

DATA SUMMARY

Palbociclib, ribociclib, and abemaciclib have exhibited superior progression-free survival differences compared to endocrine therapy alone. However, there are differences among the various CDK4/6 inhibitors with regard to overall survival, tolerability and quality of life.

CONCLUSIONS

Ribociclib may be indicated for pre/perimenopausal patients, whereas abemaciclib is potentially recommended to address endocrine-resistant or visceral disease. Alternatively, palbociclib is associated with lower discontinuation rates than abemaciclib and unlike ribociclib, QTc prolongation is not observed with palbociclib.

Current analysis of the survival implications for minimally invasive surgery in the treatment of early-stage cervix cancer

Early-stage cervical cancer (ESCC) is managed with radical hysterectomy, a procedure that can be performed either via open surgery or minimally invasive surgery (MIS), the latter of which is accomplished via traditional laparoscopy or robotic-assisted surgery. Previously, MIS was routinely incorporated into the management of ESCC due to the approach's reduced operative morbidity and truncated hospital stay duration, but more recent clinical evidence has since impugned the efficacy of MIS because of the reportedly inferior disease-free survival and overall survival outcomes compared to open surgery. However, additional studies have documented equivalent outcomes among the various surgical modalities, suggesting further exploration of clinical factors as we endeavor to conclusively determine the standard of care for patients diagnosed with ESCC.

A phase II, open-label, non-randomized, prospective study assessing paclitaxel, carboplatin and metformin in the treatment of advanced stage ovarian carcinoma

OBJECTIVE

The purpose of this study was to assess the efficacy and tolerability of a paclitaxel, carboplatin and metformin regimen in the first-line treatment of advanced-stage ovarian, fallopian tube, and primary peritoneal carcinoma.

METHODS

Eligible subjects underwent surgery and 6 cycles of neoadjuvant or adjuvant dose-dense intravenous paclitaxel (80 mg/m²), carboplatin (area under the curve 5 or 6 on Day 1), and oral metformin (850 mg daily). Study participants who completed their primary therapy and attained a clinically defined complete or partial response (PR) were treated with a planned 12 cycles of paclitaxel (135 mg/m² every 21 days) and metformin (850 mg twice daily) maintenance therapy.

RESULTS

Thirty subjects received a median of 6 cycles (range, 5-6) of primary induction chemotherapy and were eligible for response evaluation; twenty-three patients exhibited a complete response, while 3 study patients obtained a PR (an overall response rate of 86.7%). Grade 3-4 hematological toxicity included neutropenia (43.3%), thrombocytopenia (10%) and anemia (36.7%). There was no incidence of grade 3-4 neuropathy although 15 patients (50%) developed grade ≤2 neurotoxicity. Additionally, we observed grade ≤2 diarrhea in 20 (66.7%) subjects. The median progression-free survival was 21 months (range, 3-52) and overall median survival was 35 months (range, 15-61). The subjects also received an aggregate 103 cycles (median, 12; range, 6-12) of maintenance chemotherapy.

CONCLUSION

The study results suggest that the combination of paclitaxel, carboplatin and metformin is associated with moderate efficacy and a reasonable toxicity profile.

Prolonged endocrine therapy in the management of hormone receptor-positive early-stage breast cancer: What is the appropriate duration?

AIM

The clinical benefits associated with 5 years of endocrine therapy in the treatment of hormone receptor-positive, early-stage breast cancer (ESBC) have been well-substantiated. However, numerous studies have reported on the results of extended (i.e., >5 years) endocrine therapy to further effectuate a clinical benefit, with varying outcomes. Hence, the purpose of this study is to review these prolonged investigations and endeavor to clarify their corresponding treatment implications.

METHODS

We reviewed the study findings from several randomized controlled trials and meta-analyses, which incorporated clinical outcomes from pre-and postmenopausal, hormone receptor-positive, ESBC patients.

RESULTS

Hormone receptor-positive, ESBC patients treated with 5 years of endocrine therapy, who are node-negative with tumors <2 cm, will unlikely benefit from five additional years of treatment. Conversely, in women with larger tumors and node-positive disease, 7-8 total years of endocrine therapy may be indicated. Ultimately, clinicians should also consider the attendant side effects from endocrine therapy, namely bone fractures, namely cardiovascular symptoms, and vasomotor symptoms, when considering the appropriate treatment regimen.

CONCLUSIONS

While increased duration of endocrine therapy may selectively accord significant clinical benefits, prior to determining the patient's treatment interval, physicians should also assess the cumulative side effects from endocrine therapy when endeavoring to maintain treatment compliance and bolster quality of life.

Hormone Therapy and Risk of Breast Cancer: Where Are We Now?

Several studies have examined the clinical benefits of hormone replacement therapy (HRT). However, because long-term use of HRT has been implicated as a risk factor for the development of breast cancer, some women remain skeptical when considering this therapy to address their vasomotor symptoms. Hence, physicians and nurses should actively engage in constructive discourse with their patients regarding HRT while specifically reviewing the potential risks of its extended use as well as provide the available medical alternatives the patients could potentially use.

Robotic-Assisted Surgery for the Treatment of Breast and Cervical Cancers

Background:

Robotic-assisted surgery facilitates the performance of numerous, complex procedures, namely conferring precision, flexibility, and control that is otherwise unavailable with conventional laparoscopy; and compared to open surgery, robotic-assisted surgery is ostensibly associated with fewer complications, reduced intraoperative complications, and shorter hospital stay duration. Nevertheless, the American College of Obstetricians and Gynecologists and the Food and Drug Administration have criticized the pervasive acceptance of robotic-assisted surgery, given the absence of randomized clinical trial data compared to traditional laparoscopy and open procedures, not to mention the increased surgical cost.

Conclusions:

While the research data continue to be borne out, surgeons should exercise considerable discretion in selecting the surgical approach from which their patients would derive the greatest clinical benefit.