High Myelosuppression Burden Observed in Chemo-Treated Patients With ES-SCLC

A new study helped experts understand how myelosuppression affects patients with extensive-stage small cell lung cancer (ES-SCLC), as it can be detrimental to the treatment process and outcomes for this patient population.¹

“By using real-world data, we can analyze a specific patient population to determine the effectiveness of specific regimens. In this particular case, we identified myelosuppression as a significant disruptor to the treatment of ES-SCLC. Moving forward, we can integrate steps to mitigate or prevent these types of adverse effects," said Lucio N. Gordan, MD, president, managing physician at Florida Cancer Specialists & Research Institute (FCS), in the press release. "Applying such learnings aligns directly with our mission of delivering patient-centered care through innovation and excellence – the best oncology care possible."

In the retrospective cohort study, structured electronic medical record (EMR) data from the FCS obtained between January 2013 and December 2020 was used and adult patients with ES-SCLC who were treated with at least 1 line of chemotherapy between September 2013 and November 2020 were identified.

The index date was the date of the first chemotherapy-containing line of therapy (LOT). Those included in the study were followed for at least 30 days after index until December 31, 2020, or end of activity in the EMR data, whichever occurred first.

Patients were required to have at least 1 encounter in the EMR system after the index treatment date and there must have been evidence of ES-SCLC in the 180 days prior to the date of first chemotherapy dose observed during the patient identification period if the index LOT was first-line therapy. Incidence and frequency of myelosuppressive episodes/events, treatment patterns, eligibility for red blood cell (RBC) or platelet transfusions, and supportive care use were reported during the follow-up period.

Investigators assessed the primary end point during follow-up of the prevalence and frequency of myelosuppressive episodes across all LOTs, and additional end points of time to myelosuppressive episodes, treatment patterns, eligibility to receive RBC or platelet transfusion, and supportive care use across all LOTs.

A total of 1239 patients were included in the study with a mean age of 66.9 (9.3) years. Male patients made up 49.7% of the population, and 58.0% were White. Most of the patients included had an ECOG performance status of 0 or 1 (64.5%), and the most common non-cancer-related comorbidities from the CCI included chronic pulmonary disease (5.5%), mild liver disease (2.3%), and renal disease (2.2%). Ninety-four percent of patients started first-line chemotherapy at the index treatment date. Additionally, the prevalence of grade ≥ 3 myelosuppressive events was low, including neutropenia (3.5%) anemia (1.6%), thrombocytopenia (1.2%), lymphopenia (2.5%), and leukopenia (2.9%), prior to index chemotherapy initiation. After index chemotherapy initiation, the mean follow-up was 10.4 (11.3) months.

The most often given index treatment was platinum/etoposide-containing chemotherapy alone (64.3%) or platinum/etoposide-containing chemotherapy in combination with immuno-oncology treatment (22.4%). A total of 94.6% of patients discontinued index treatment during follow-up. Of the patients who discontinued, the median time to discontinuation was 3.5 months. About half (52.8%) of the patients included were given at least 1 subsequent LOT, and the median time to next treatment from the start of the index LOT was 4.6 months among patients who initiated subsequent therapy. Patients received a median number 2 regimens. Among the 2336 regimens received across all LOTs, 52.2% were platinum-based and 8.1% were topotecan-containing chemotherapy.

When looking at myelosuppressive episodes and events, 1222 (98.6%) patients had at least 1 myelosuppressive episode during follow-up and across all chemotherapy-containing LOTs. A total of 62.1% of patients had grade ≥ 3 myelosuppressive episodes in at least 1 lineage, while 33.9% had grade ≥ 3 myelosuppressive episodes in at least 2 lineages, and 15.5% had grade ≥ 3 myelosuppressive episodes in all 3 lineages. Decreases across all peripheral blood lineages in all LOTs were observed in 48.6% of patients.

Among patients who had available laboratory data to allow for the grading of chemotherapy-induced myelosuppression events, 26.5% and 26.9% of patients had grade 3 and grade 4 neutropenia, respectively, while 32.7% had grade 3 anemia, and 31.0% and 16.1% had grade 3 and grade 4 thrombocytopenia, respectively. There were similar results observed when the prevalence of myelosuppressive events were compared during the index LOT and all LOTs.

There were 419 (33.9%) patients who had grade ≥ 3 neutropenia, thrombocytopenia, and/or anemia episodes in at least 2 lineages, and of the patients with laboratory data, 20.6% patients had grade 3 anemia and grade ≥ 3 neutropenia. Additionally, 21.5% patients had grade 3 anemia and grade ≥ 3 thrombocytopenia, and 22.8% patients had grade ≥ 3 neutropenia and grade ≥ 3 thrombocytopenia. Another 15.5% patients had grade ≥ 3 myelosuppressive episodes in all 3 lineages.

With a cumulative time on chemotherapy at 3, 6, and 12 months, 37.2%, 45.2%, and 57.0% of patients had grade ≥ 3 neutropenia, 26.7%, 36.7%, 45.3% had grade 3 anemia, and 29.5%, 41.8%, 49.0% had grade ≥ 3 thrombocytopenia.

Use of supportive care included 89.7% of patients who were given G-CSF, 24.4% who received ESAs, and 52.1% who received intravenous volume expansion. Additionally, 32.6% of patients were eligible to receive RBC transfusions based on lab values.

Overall, the study showed that there is a high burden related to multilineage myelosuppression among patients with ES-SCLC in the community oncology setting who are chemotherapy-treated. Working to reduce myelosuppression could make treatment with chemotherapy safer, lead to a reduction in the need for supportive care and can potentially prevent complications among patients.

"Myelosuppression is a highly prevalent issue when treating ES-SCLC. It can be detrimental to the treatment process and outcomes, often causing delays in care and added complications. Conducting this study was an important step to understanding how it affects this highly vulnerable patient population," said Lowell L. Hart, MD, FACP, medical oncologist at FCS who also served as first author for the study, in the press release.

REFERENCES:

1. New study evaluates effects of chemotherapy-induced myelosuppression for extensive-stage small cell lung cancer, data from florida cancer specialists & research institute. News release. Florida Cancer Specialists & Research Institute. April 13, 2023. Accessed April 13. 2023. https://prn.to/3KDU77Y

2. Hart L, Ogbonnaya A, Boykin K, et al. Burden of chemotherapy-induced myelosuppression among patients with extensive-stage small cell lung cancer: A retrospective study from community oncology practices [published online ahead of print, 2023 Mar 31]. Cancer Med. 2023;10.1002/cam4.5738. doi:10.1002/cam4.5738