1 Introduction

The COVID-19 pandemic has resulted in changes worldwide with significant socio-economic and healthcare implications. During this exceptional time, the care for cancer patients has been compromised due to diversion of healthcare resources towards battling the pandemic, with an anticipation of increased cancer mortality rate in the coming years [1]. The timely diagnosis and management of cancer is paramount. On the other hand, as cancer patients are at higher risk of complications and worse outcomes from COVID-19 infection [2], ensuring prompt cancer treatment whilst limiting their exposure to COVID-19 remains a challenge.

Worldwide, there are many layers in cancer care that have been affected, from screening, biopsies, laboratory analysis, imaging, surgery, chemotherapy and radiotherapy; not just the actual service but also the supply chain, technical maintenance and patient access [3]. City lockdowns, movement restrictions, increased burden of primary and secondary care in managing COVID-19 patients and suspected cases, and internalized fear of the general population to leave the safety of their homes contribute to reduced medical seeking behaviour with resulting delayed diagnosis, higher tumour staging and possible poor survival outcomes. Even with timely presentation, the prioritization of healthcare resources in containing and treating COVID-19 patients means that the delay in providing time-sensitive and life-saving cancer treatment was inevitable [4-6]. We may foresee higher cancer stages and an overall increase in cancer mortality in the years to come as a result of COVID-19.

In Singapore, the first few imported cases of COVID-19 were detected in mid to late January 2020, with the country subsequently gradually raising the alert level from early February to March 2020, along with advice and restrictions to stay home and avoid going out unless for essential tasks and errands. This culminated in Singapore going into a lockdown from 7th April to 1st June 2021 over a period of 8 weeks at the peak of COVID-19 infection to curb transmission of unlinked infections (Fig. 1). The total number of COVID-19 infections during that period was about 45,000, with foreign workers living in dormitories forming the main affected population [3]. As a result, for the most part of the first half of 2020, the country’s healthcare system has had to pre-emptively restructure its services to cope with the burden of the pandemic by limiting unnecessary hospital visits, reducing non-essential services and focusing manpower and resources to managing COVID-19-related issues. In addition to this, stringent checks on travel history, body temperature, as well as the presence of any possible COVID-19 symptoms were instituted at all healthcare institutions in order to reduce the risk of healthcare – associated transmissions, which may serve to further impact the medical seeking behaviour of patients.

Fig. 1
figure 1

Timeline of Singapore’s COVID-19 situation and response measures

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In this paper, we aim to investigate the impact of the COVID-19 pandemic on cancer care in our institution via a review of our nasopharyngeal carcinoma (NPC) case numbers. We specifically decided to look at nasopharyngeal carcinoma as a bellwether of our management of other cancer conditions in our centre during the pandemic, for the following reasons:

  • 1. The management of this cancer has a clear standardized algorithm of management from diagnosis to treatment in our centre,

  • 2. The majority of the treatment is managed and coordinated by a single provider (the radiation oncologist),

  • 3. There is the ability to identify clear and consistent care delivery time points,

  • 4. Our institution has historically treated the highest proportion of nasopharyngeal carcinoma patients nationally.

Singapore has one of the highest rates of NPC in the world at 6.7 per 100,000 [7]. In Singaporean males, nasopharyngeal cancer is in the top 10 most frequently occurring cancer in those aged 30–50 years old and the 8th most frequent cancer death [

Fig. 3
figure 3

Number of newly diagnosed NPC patients in the month of January to 31st May for the years 2017 to 2020

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There was no statistically significant difference in the age demographics of the patients, with the largest number of patients coming from the 51 to 70 years age group in all the 4 years, as per the natural history of NPC. The COVID-19 pandemic peak did not appear to alter the health seeking behaviour of the patients across the age groups. More male patients than female presented in 2020 (89.7% vs 10.3%), compared with that of previous years.

Table 1 shows the NPC disease stages at presentation for each year, as well as the data for the time points of interest, namely:

  • i) the duration of symptoms prior to initial presentation. Most, if not all NPC patients will get their biopsy performed during the first visit at initial presentation, as the diagnostic method is via post-nasal space biopsy, which is performed as an in-clinic procedure.

  • ii) the days from biopsy to the patient’s first Radiation Oncology visit in our centre.

  • iii) the duration from biopsy to the first day of treatment.

Table 1 Disease and treatment characteristics
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Radical treatment for NPC generally falls into 3 regimens;

  • 1. radiation therapy (RT) alone, which is generally used in Stage I and early Stage II disease, or in patients unfit to receive any chemotherapy (AJCC 8th edition).

  • 2. concurrent chemoradiation therapy, which is generally used in some Stage II and selected Stage III disease.

  • 3. induction chemotherapy for 3 cycles, then concurrent chemoradiation therapy for more advanced disease or concurrent chemoradiation followed by adjuvant chemotherapy.

We analysed the data for each treatment regimen separately due to the different treatment planning duration needed for each regimen. For example, radiation therapy treatment planning in our centre takes an average of 10 to 14 days of planning time, which is not required in cases where the first treatment the patient receives is induction chemotherapy.

Another caveat in analyzing the data would be that the induction chemotherapy followed by concurrent chemoradiation treatment for advanced NPC (Stage III and up, excluding cT3N0M0 disease) only gained traction in mid to late 2019 after positive Phase III trial data [9], thus most of these patients received concurrent chemoradiation in the prior years.

There was a reduction of 37–46.3% in newly diagnosed NPC during the peak of the COVID-19 pandemic months of January to June 2020 (n = 29) compared to the same months in the preceding three years. However, no trend in stage migration to higher numbers of Stage III and IV disease was observed, with a comparable percentage of patients presenting consistently for each stage of disease.

We also did not observe any delay in presentation during the COVID-19 peak months in 2020 compared with previous years, with the majority (79.3%) of patients presenting within 90 days from development of initial symptoms.

Importantly, there was no delay in delivery of service by our centre during the peak COVID-19 pandemic period. We were able to keep consistently to seeing the patient within 2 weeks of biopsy (median = 13 days), which is similar to our median data across previous years. Also, for patients who received a radiation – based regimen (radiation therapy alone or concurrent chemo-radiation), there was no change in the median number of days taken from biopsy to first day of treatment, with a median of 35 to 37.5 days.

A comparison of the 3 – year survival data for each of the cohorts was also carried out, with the cut-off for analysis of the 2017 cohort at end – 2019, 2018 at end – 2020, 2019 at end – 2021 and 2020 at end – 2022. While the overall sample size was small, thus limiting statistical inference, both 3 – year local recurrence (LR) and distant metastasis (DM) rates appear to be higher than previous cohorts in 2018 and 2019, at 20.6% and 17.2% respectively. In addition, there were 2 patients with early—stage NPC who recurred within 3 years. 1 patient with Stage I disease developed both LR and DM, while another with Stage II disease developed LR. Both patients did not delay from development of initial symptoms to presentation at the ENT clinic; however, both patients did have a delay from biopsy to first Radiation Oncology clinic visit (27 days and 41 days; median 13 days), as well as a resulting delay from biopsy to commencement of treatment (59 days and 78 days; median 33 days). A deeper multi – centre and possibly international study would be of interest to further investigate this trend.