Patients with advanced breast cancer should receive COVID-19 vaccinations as soon as possible and the second dose should be delivered early, no later than three to four weeks after the first, the virtual meeting of the Advanced Breast Cancer Sixth International Consensus Conference (ABC 6) heard today (Friday). 
Dr Alexandru Eniu (MD, PhD), medical oncologist and chief physician at the Hôpital Riviera-Chablais, Rennaz, Switzerland, told the meeting that evidence to date showed that vaccines were safe for cancer patients, with no notable differences between different brands. However, vaccines based on inactivated viruses should not be used in cancer patients . In addition, he said vaccination should not be delayed for patients who are taking part in clinical trials for cancer treatments, and nor should vaccination preclude patients from being included in these trials.
For patients with solid tumours such as breast cancer, research shows that 80% had immune responses after the second dose.
“Although the magnitude of the vaccine-induced immune response is somewhat reduced in patients with cancer, it is still better than nothing and may protect them against COVID-19. Antibody responses should be interpreted with caution as they are only an indicator of the possible protection provided by the vaccine; however, the evidence indicates that vaccinations should be prioritised in all cancer patients and the benefits outweigh any risks,” said Dr Eniu, who is also deputy scientific director and chair of the European School of Oncology.
“Several studies so far show that COVID-19 vaccinations are safe for cancer patients, with no or only mild side effects. Importantly, for patients who are being treated with immunotherapies, as is the case for many patients with advanced breast cancer, the vaccine does not exacerbate immune-related side effects. Even in patients who had experienced previous side effects related to their immunotherapy, the vaccine-related side effects are mild. The same is also true for those being treated with chemotherapy.”
Highlighting a recent study of the Moderna vaccine , he said that a significant minority of cancer patients with solid tumours do not develop an adequate antibody response to the coronavirus: 7% in patients receiving immunotherapy, 16% in patients receiving chemotherapy and 11% of patients receiving both. “In addition, only a third of the patients have an adequate antibody response after one vaccination, which is why the second dose is so important,” he said.
At the start of the pandemic, cancer doctors faced uncertainty over the best ways to care for their patients. “We had to learn as we went along,” he said. “We now have answers to many questions. However, we are still unsure which level of antibodies is high enough to be an effective protection against COVID-19 and how long the protection lasts. There is not enough evidence yet about the effectiveness of additional, booster vaccinations, or whether alternative measures are required. One study showed that in a small group of just 20 patients who received a third dose of vaccine, there was a modest but consistent, statistically significant increase in antibodies. Current guidelines recommend a third dose for moderately to severely immunocompromised patients within a year from the first dose and at least four weeks after the second dose.”
He called for global efforts to improve the current inequality in planning, funding, procuring and rolling out of effective vaccination programmes.
“Global access has not been equitable. High income countries dominate access to vaccine supplies and COVAX only covers 20% of the populations of recipient countries. Some populations have no access to vaccines of any type. There is an urgent need for vaccination programmes to be rolled out. It is very important that they should include cancer patients, their caregivers and healthcare workers,” Dr Eniu concluded.
In a second presentation, Dr Laura Biganzoli (MD), acting director of the Division of Medical Oncology and director of the Breast Centre at Santo Stefano Hospital, Prato, Italy, said: “The COVID-19 pandemic has created many and unexpected challenges. We found ourselves facing an emergency without knowing exactly how to act. But it has also revealed opportunities to improve patient care.”
She and colleagues around the world quickly put in place measures to try to deliver the best possible care to patients, often remotely, while reducing the risk of vulnerable patients being exposed to infection with COVID-19. These included meetings between different health professionals involved in a patient’s care taking place via videoconferencing, relying more on their own clinical judgement and depending less on the results of imaging and radiological investigation of the tumour’s response to treatment, patient consultations held remotely via telephone or online, enabling medicines to be collected from places outside the hospital, and the ability to administer medications at home. Doctors also considered more carefully the likelihood of real benefit of treatments offered to patients after previous ones had failed, and whether patients might benefit from “holidays” from treatment.
However, Dr Biganzoli said that although these measures had the potential to make cancer services more accessible in the longer term, they came at a cost.
“In my experience, patients and their family members found it difficult to accept measures that introduced a physical distance between them and clinicians. This was particularly the case for frail and older patients. Empathy and sometimes physical contact are essential components in the management of metastatic breast cancer patients. COVID deprived us of this and it’s not easy to transmit it virtually. This has reinforced our determination not to let our patients feel alone, and the importance of collaboration with the caregiver.”
Chair of the ABC 6 conference, Dr Fatima Cardoso, Director of the Breast Unit of the Champalimaud Clinical Centre in Lisbon, Portugal, who was not involved with the research, said: “These two presentations provide some answers and reassurance to our patients with advanced breast cancer in relation to the COVID-19. They show how we are adapting to the challenges presented by the pandemic so that we can continue to provide the best possible care for our patients. They also highlight the emotional and psychological impact of the pandemic on cancer patients and their caregivers. Telemedicine has advantages but also several drawbacks, especially for advanced cancer patients.
“Professor Eniu’s presentation underlines the importance for everyone, especially breast cancer patients, to be protected from COVID-19 infection by being vaccinated as soon as possible if you have not been already. For cancer patients who have received vaccination while on immunosuppressive treatments, a third dose needs to be considered. This will save lives.”
 Around 1,000 participants from countries all over the world are attending the Advanced Breast Cancer Sixth International Consensus Conference (ABC 6). This year the meeting has moved online from its normal venue in Lisbon, Portugal, due to the COVID-19 pandemic.
 COVID-19 vaccines based on inactivated viruses include: Sinovac-CoronaVac, Sinopharm BIBP, Bharat Biotech Covaxin (BBV152).
 Oosting et al, Annals of Oncology (2021) 32 (suppl_5): S1283-S1346.
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“The ABC of COVID-19 vaccination for advanced breast cancer patients”, by Dr Alexandru Eniu; “Lessons learned from COVID-19: a personal point of view of a medical oncologist”, by Dr Laura Biganzoli