Volume doubling time in early stage lung cancer

Change in Lung Cancer Stage in the interval between CT and histopathological diagnosis:

A study has sought to quantify the change in tumour size and T-stage between diagnosis (CT) and treatment (surgical resection), as defined by updated staging guidance, and its impact on recurrence and survival in non-small cell lung cancer (NSCLC) (1)

• data on 289 patients resected in 2015/2016 in a single tertiary centre (Clydebank) were analysed including measurements of tumour size from diagnostic CT, staging PET-CT and histopathological assessment of resected tumour
• in the interval between CT and PET-CT (median 26 days), 47% had an increase in tumour size and 33% were T-upstaged
• in the interval between CT and histopathology (median 74 days), 62% had an increase in tumour size and 46% were T-upstaged, 23% by more than one T-stage
  • patients that were T-upstaged had a shorter mean survival and mean recurrence free survival
  • T-upstaging was independently associated with reduced overall survival (when histology, grade of differentiation, age, sex, tumour size at diagnosis were taken into account)

Commentary:

• whilst this study has some limitations (single centre, retrospective, doesn’t consider some relevant factors), the findings suggest that reducing the intervals between diagnosis, staging and treatment could help to improve outcomes for patients undergoing surgery

Volume Doubling Time in Early Stage Lung Cancer:

The volume doubling time (VDT) of lung cancer is evidenced from this study by Frelinghuysen M et al (1)

This study investigated inoperable patients and prognosis and VDT of lung cancer - to investigate its consequence with regard to staging and survival in 117 inoperable patients with early stage lung cancer treated with stereotactic body radiotherapy.

VDT was defined as fast (<100 days), moderate (100-249 days), slow (250-399 days), and no growth (=400 days).

The VDT was fast in 53 patients [45%] of tumors. No significant difference in VDT was found between different tumor or patient characteristics. Patients with T1 tumors that progressed to T2 had a significant worse median survival (P = .01). The overall survival at 5 years according to VDT was 21% for fast-growing tumors, 19% for moderate growth, 31% for slow, and 46% for no growth.

VDT was considered as fast in almost half of tumors examined. This resulted in significant growth and upstaging in 35% of the tumors, with a significant worse survival if T1 tumors progressed to T2 tumors. Therefore, medically inoperable patients should also be offered a fast workup and referral.

With respect to lung cancer growth:

• this study revealed volume doubling time was fast (<100 days) in almost half of early stage lung cancers - this has implications for the value of fast workup and referral in all patients with early stage lung cancer

References:

• McPherson et al. The progression of non-small cell lung cancer from diagnosis to surgery. Eur J Surg Oncol. 2020. 15;S0748-7983(20)30705-8
• Frelinghuysen M et al. Consequences of Referral Time and Volume Doubling Time in Inoperable Patients With Early Stage Lung Cancer.Clin Lung Cancer. 2017 Nov;18(6):e403-e409.