# Unraveling Ductal Carcinoma In Situ in an Unscreened Population: Understanding Its Natural History Through Advanced Presentation and Management

## TL;DR

This study examines how ductal carcinoma in situ (DCIS) behaves in populations without regular breast cancer screening, finding that it tends to be more aggressive and often progresses to invasive cancer.

## Contribution

The study provides insights into DCIS natural history in unscreened populations, highlighting aggressive features and higher progression rates compared to global averages.

## Key findings

- DCIS in unscreened populations presents with larger, higher-grade tumors and a 39.9% upgrade rate to invasive carcinoma.
- Only 3.5% of DCIS cases were detected via screening, with most presenting as palpable lumps.
- Mastectomy and sentinel lymph node biopsy were required in over half of the cases due to advanced disease presentation.

## Abstract

Background: Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer with debated management strategies, particularly in unscreened populations where delayed detection often leads to advanced presentations. Understanding DCIS in this context is crucial for improving risk stratification, treatment, and outcomes.

Objective: This study aims to explore the clinicopathologic features, progression, and outcomes of DCIS in an unscreened population, comparing findings with national and international studies.

Methods: We conducted a retrospective analysis of 172 patients diagnosed with isolated DCIS at Liaquat National Hospital and Medical College, Karachi, Pakistan, from January 2019 to December 2023. Data collected included demographics, presenting symptoms, imaging findings, biopsy methods, histopathologic features, and treatment details. Statistical analysis was performed using SPSS Statistics for Windows, Version 25 (Released 2017; SPSS Inc., Chicago, United States), with p ≤ 0.05 considered significant.

Results: Of 4690 breast cancer cases, 3.6% were isolated DCIS. The median age was 51 years, with 66% postmenopausal. The most common symptom was a palpable lump (68%), with only 3.5% detected via screening. High-grade DCIS was prevalent (41.7%), with comedo necrosis in 23.7%. Tumor size exceeded 5 cm in 25.8% of cases. Breast-conserving surgery (BCS) was performed in 39.9% of patients, with a 15.4% re-surgery rate. Mastectomy and sentinel lymph node biopsy were required in 56.6% of cases. The upgrade rate to invasive carcinoma was 39.9%, higher than global averages. Estrogen receptor positivity was noted in 70.9% of patients.

Conclusion: DCIS in unscreened populations presents more aggressively, with larger, higher-grade tumors and a significant risk of progression to invasive disease. The findings emphasize the need for targeted screening and tailored management strategies to improve outcomes. Future research should focus on optimizing diagnostic and therapeutic approaches in such high-risk groups.