# Active surveillance and observation

Source: https://onco.cc/terms/active-surveillance-term/  
OnCo record `active-surveillance-term` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Deliberately not treating a cancer yet, but checking it regularly with blood tests, scans or biopsies and treating only if it shows signs of progressing. Standard for low-risk prostate cancer, small kidney masses and several other slow conditions.

## Summary

Active surveillance avoids or defers the harms of treatment for cancers unlikely to cause trouble: Grade Group 1 prostate cancer (ProtecT showed no survival penalty at 15 years), small renal masses, papillary thyroid microcarcinoma, low-risk DCIS (COMET), smouldering myeloma and early-stage CLL, and stage I testicular cancer after orchiectomy. It differs from watchful waiting, which forgoes curative intent. 'Surveillance' also describes the scheduled follow-up after curative treatment (CT, ctDNA, MRI in small-cell lung cancer instead of prophylactic cranial irradiation), and after complete response in organ-preservation strategies (SANO in oesophageal cancer).

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: active surveillance; watchful waiting; expectant management; surveillance MRI; imaging surveillance; surveillance imaging; wait-and-see; surveillance strategy; post-treatment surveillance; follow-up imaging

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Active_surveillance_of_prostate_cancer
- Wikipedia: https://en.wikipedia.org/wiki/Active_surveillance_of_prostate_cancer

## Connected records

- technologies: [Active surveillance](https://onco.cc/technologies/active-surveillance/)
- terms: [Cambridge Prognostic Group (CPG 1 to 5)](https://onco.cc/terms/cambridge-prognostic-group/), [Choosing treatment for localised prostate cancer: what each option costs](https://onco.cc/terms/prostate-treatment-choice-localised/), [Cribriform growth pattern in prostate cancer](https://onco.cc/terms/cribriform-prostate-cancer/), [Ductal carcinoma in situ (DCIS)](https://onco.cc/terms/dcis/), [Focal and tissue-preserving treatment of prostate cancer](https://onco.cc/terms/prostate-focal-therapy/), [Gleason score / Grade Group](https://onco.cc/terms/gleason-grade-group/), [Organ preservation (watch-and-wait, bladder-sparing, larynx preservation)](https://onco.cc/terms/organ-preservation/), [Overtreatment](https://onco.cc/terms/overtreatment/), [Percentage of Gleason pattern 4](https://onco.cc/terms/percentage-gleason-pattern-4/), [PSA density](https://onco.cc/terms/psa-density/), [PSA kinetics: PSA doubling time and PSA density](https://onco.cc/terms/psa-kinetics/), [Smouldering myeloma / MGUS](https://onco.cc/terms/smoldering-myeloma/), [Watchful waiting, and how it differs from active surveillance](https://onco.cc/terms/watchful-waiting/)
- cancers: [Chronic lymphocytic leukaemia](https://onco.cc/cancers/cll/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Renal cell carcinoma](https://onco.cc/cancers/rcc/), [Thyroid cancer](https://onco.cc/cancers/thyroid/)
- fronts: [Diagnostics & Biomarkers](https://onco.cc/fronts/diagnostics/)
- trials: [PIVOT (Prostate Cancer Intervention Versus Observation Trial)](https://onco.cc/trials/pivot/), [ProtecT](https://onco.cc/trials/protect/), [SANO](https://onco.cc/trials/sano/), [SPCG-4 (Scandinavian Prostate Cancer Group Study 4)](https://onco.cc/trials/spcg-4/)
- drugs: [Oncotype DX Genomic Prostate Score](https://onco.cc/drugs/oncotype-dx-gps/), [Padeliporfin](https://onco.cc/drugs/padeliporfin/), [Prolaris](https://onco.cc/drugs/prolaris/)

---
JSON: https://onco.cc/api/v1/entities/active-surveillance-term.json