Expert UK consensus on the definition of high risk of recurrence in HER2-negative early breast cancer: A modified Delphi panel

BACKGROUND

There is currently no standardised definition for patients at high risk of recurrence of human epidermal growth factor receptor 2 (HER2)-negative early breast cancer (eBC; stages 1-3) after surgery. This modified Delphi panel aimed to establish expert UK consensus on this definition, separately considering hormone receptor (HR)-positive and triple-negative (TN) patients.

METHODS

Over three consecutive rounds, results were collected from 29, 24 and 22 UK senior breast cancer oncologists and surgeons, respectively. The first round aimed to determine key risk factors in each patient subgroup; subsequent rounds aimed to establish appropriate risk thresholds. Consensus was pre-defined as ≥70% of respondents.

RESULTS

Expert consensus was achieved on need to assess age, tumour size, tumour grade, number of positive lymph nodes, inflammatory breast cancer and risk prediction tools in all HER2-negative patients. There was additional agreement on use of tumour profiling tests and biomarkers in HR-positive patients, and pathologic complete response (pCR) status in TN patients. Thresholds for high recurrence risk were subsequently agreed. In HR-positive patients, these included age <35 years, tumour size >5 cm (as independent risk factors); tumour grade 3 (independently and combined with other high-risk factors); number of positive nodes ≥4 (independently) and ≥1 (combined). For TN patients, the following thresholds reached consensus, both independently and in combination with other factors: tumour size >2 cm, tumour grade 3, number of positive nodes ≥1.

CONCLUSIONS

The results may be a valuable reference point to guide recurrence risk assessment and decision-making after surgery in the HER2-negative eBC population.

A phase I study of oral rucaparib in combination with carboplatin

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Background: Targeting poly (ADP-ribose) polymerase (PARP), an enzyme involved in DNA damage repair, may increase efficacy of DNA-damaging agents. This study evaluated the tolerability of oral rucaparib, a potent and selective PARP1/2 inhibitor, in combination with carboplatin (CP). Methods: Patients (pts) aged ≥18 with advanced solid tumors were included. Pts received lead-in doses of IV and oral rucaparib on Days -10 and -5, respectively, followed by CP on Day 1 and oral rucaparib on Days 1-14 q21 days. Treatment continued until disease progression. Pts with benefit could continue on rucaparib monotherapy once CP dosing was completed. Dose escalation was based on toxicities observed in Cycle 1 in cohorts of n=3-6. PK was assessed during Cycle 1. Results: 23 pts (median age 62 yrs [range 20 – 76]; 16 female; 9 ECOG PS=0; 6 ovarian/peritoneal cancer (OC), 5 breast cancer (BC), 2 NSCLC, 10 other tumor) were enrolled. Rucaparib doses of 80, 120, 180, 240, and 360 mg were administered with AUC3 CP, followed by 360 mg rucaparib with AUC4 CP, and currently with AUC5 CP. No DLTs have been reported. Median treatment cycles is 3 (range 1 – 15+). Treatment-related adverse events in ≥4 pts, all grades, include anemia (n=10), fatigue (n=9), nausea (n=7), thrombocytopenia (n=6), constipation (n=5), lethargy (n=5), neutropenia (n=5), and anorexia (n=4). One pt (OC, BRCAwt, AUC3 CP/180 mg rucaparib) had a PR of 5.1 mo duration. Two patients (both with OC; 1 BRCAunk, 1BRCAwt) discontinued CP (after 4 & 8 cycles) and continued on rucaparib monotherapy (additional 5 and 7+ cycles, respectively). An additional 4 pts (all BRCAunk) had stable disease (SD) >12 wks. Overall disease control rate (CR+PR+SD>12 wks) in OC pts across all dose levels was 50% (3/6). Dose-proportional increase in rucaparib exposure was observed with steady state achieved by Day 14 and mean t1/2of 15 h. Oral bioavailability was 38% and dose-independent. Rucaparib exposure was not changed by CP co-administration. Conclusions: The combination of oral rucaparib and CP is well tolerated and exhibits activity at clinically relevant doses of each agent. Further studies in platinum-sensitive and homologous recombination repair deficient populations are warranted. Clinical trial information: NCT01009190.

Final results of the phase I trial of niraparib (MK4827), a poly(ADP)ribose polymerase (PARP) inhibitor incorporating proof of concept biomarker studies and expansion cohorts involving BRCA1/2 mutation carriers, sporadic ovarian, and castration resistant prostate cancer (CRPC)

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Background: Niraparib(N) is an oral, potent PARP1/2 inhibitor that induces synthetic lethality in BRCA1/2 deficient tumors. PARP is also implicated in transcription regulated by the androgen receptor (AR) and rearranged ETS genes; key targets in CRPC. Methods: Dose-escalation was enriched for BRCA1/2mutation carriers (BRCA-MCs). Two MTD expansion cohorts were undertaken in patients (pts) with sporadic high grade serous ovarian cancer (HGSOC) and CRPC. In CRPC pts, archival tissue and circulating tumor cells (CTC) were analyzed for PTEN deletion and ETS gene rearrangements. Results: 100 pts [ovary (49), CRPC (23), breast (12) others (16)], received N at 10 dose levels: 30mg to 400mg daily (od), continuously. Grade (G) 4 thrombocytopenia was dose limiting at 400mg od; MTD was established at 300mg od. Drug-related toxicities were G1-2 reversible anemia (48%), fatigue (42%), nausea (42%), thrombocytopenia (35%), anorexia (27%), neutropenia (24%), constipation (23%), and vomiting (20%). PKs were dose proportional with a mean elimination t1/2of 40 hours. Peripheral blood mononuclear cells had >50% PARP inhibition from 80 mg od. gH2AX foci formation, a marker of DNA damage, was seen in CTCs. Antitumor activity occurred from 60mg od with RECIST and/or CA125 partial responses (PR) in 9/20 (45%) BRCA-MC ovarian cancer pts and 2/4 (50%) BRCA-MC breast cancer pts. Platinum-sensitive vs resistant BRCA-MC HGSOC response rate was 60% vs 33% with median time for responding pts of 429 and 340 days, respectively. In sporadic HGSOC, there were 2/3 PRs in platinum-sensitive pts, and 3/20 PRs plus 4/20 stable disease (SD) >16 weeks in platinum resistant pts. In CRPC, symptomatic benefit and SD >6 months (median 9 months) was seen in 9/21 (43%) pts treated at MTD. CTC declines of >30% (median 80%; range 36%-92%) were observed in 7/10 (70%) pts with evaluable CTC counts (≥5 cells/ 7.5mL blood). Conclusions: Niraparib was well tolerated and has promising antitumor activity in BRCA-MCs, sporadic HGSOC and CRPC. Clinical trial information: NCT0074902.

The frequency and severity of capecitabine-induced hypertriglyceridaemia in routine clinical practice: a prospective study

Background:

Capecitabine is known to rarely cause raised serum triglycerides (TG). In our centre, several patients receiving capecitabine developed raised TG levels corresponding to the ‘very high risk’ category for potentially serious acute pancreatitis.

Methods:

A fasting blood lipid screening protocol was introduced into clinical practice for patients receiving capecitabine. Patients with TGs >5 mmol l⁻¹ were treated and followed up. An 18-month prospective audit was performed to establish the incidence and severity of capecitabine-induced hypertriglyceridaemia (CIHT).

Results:

A total of 304 patients received capecitabine for colorectal cancer between January 2008 and June 2009. Of these, 212 patients (70%) were screened and 8 (3.7%) developed clinically significant hypertriglyceridaemia requiring lipid-lowering therapy. Two of the eight patients had diabetes and one had pre-existing dyslipidaemia. One suffered cerebral infarction during chemotherapy. There were no cases of acute pancreatitis. Follow-up showed that serum TGs safely and rapidly returned to normal with appropriate treatment without discontinuation of capecitabine.

Conclusions:

This is the first prospective study evaluating CIHT. These results suggest that it should be classed as a ‘common’ undesired effect of capecitabine. Despite this, the incidence does not justify routine screening in all patients. Targeted screening in those with diabetes or pre-existing hyperlipidaemia is recommended, together with adoption of a clear management policy.