Clinical presentations and outcomes of young women aged <40 yrs with Ductal carcinoma in situ

Young women <40years old with DCIS accounted for 9.0% of all patients with DCIS in our cohort. Majority of patients were symptomatic with 73.2% of patients presenting with symptoms. Breast lump was the most common reason for presentation. Majority (63.4%) of patients underwent breast conserving surgery, with 34.6% of these patients also receiving adjuvant radiotherapy. ER positive disease was present in 86.8% of patients of which 15.2% received hormonal therapy. Patients presenting with symptoms had higher grade (p = 0.0090). Recurrence was not statistically significant between cases presenting with symptoms versus those who did not. To the best of our knowledge, this is the first study comparing outcomes in young women with DCIS presenting with symptoms versus those who did not.

DCIS is diagnosed almost solely by mammogram, and its incidence has been increasing due to widespread use of mammogram screening. Locally, DCIS accounted for 26% of all screen-detected breast cancers [11]. Mammogram screening is recommended every 2 years for ages ≥50 years. At 40–49 years of age, mammogram screening could be offered annually, after a discussion of its risks and benefits. For younger women of average risk aged <40 years, only monthly breast self-examination is advocated. This local screening guideline was formulated because DCIS constituted >30% of all breast cancers among pre-menopausal women, which largely constituted women aged 40 to 49 years [11].

DCIS is uncommon in young women, and because they do not qualify for mammogram screening, most of these young women with DCIS presented with symptoms. In our study, these patients who presented with symptoms tended to exhibit higher grade compared to those who did not present with symptoms. Although the literature indicates high grade as a risk factor for recurrence [12,13], our study showed that the mode of presentation was not a statistically significant risk factor for recurrence, even though all recurrences occurred in the symptomatic group. This may be due to the small numbers in our study and there may be other implicating risk factors for recurrence.

Patients <40 years old diagnosed with DCIS have generally been shown to have a poorer prognosis with a tendency towards higher recurrence [14--16], although some studies have shown that young age alone is not a significant predictor of poor prognosis [12]. As a result, there was a trend in some countries for younger women with DCIS to opt for mastectomy as well as contralateral risk reducing mastectomy [17,18]. A recent study, however, cautioned against excessively aggressive treatment, as mastectomy did not offer better survival benefits over breast conserving surgery with radiotherapy [14]. In our study, although the majority of cases underwent breast conservation surgery, our recurrence rate was comparable with the literature, which reported a 5-year local recurrence rate of 10.1% in women aged <40 years [13].

While radiotherapy following breast conserving surgery confers a risk reduction of ipsilateral tumour recurrence, this risk reduction of adjuvant radiotherapy appeared to be smaller in younger women aged <40 years old [19]. The role of adjuvant radiotherapy in young patients with DCIS needs to be clarified with further studies.

Adjuvant endocrine therapy in hormone positive DCIS has been purported to decrease invasive recurrence, although it has not been established to improve survival [20]. A recent large study reported an uptake of endocrine therapy in young women with DCIS aged ≤30 at 18.1% [20], which was comparable with our study. Patient refusal was one of the reasons cited for the low uptake of endocrine therapy. This was likely due to perceived side effects of endocrine therapy and its effects on fertility.

There is currently no consensus whether younger patients with DCIS should be treated more aggressively. This is because not only are they relatively rare, there were different age cut-offs used in various studies to define young patients with DCIS, with some studies using <35, <40 and even <50 years old as a cut-off age. In this study, <40 years old was chosen as the cut-off age because mammography screening is offered locally to patients aged ≥40 years. Nevertheless, with the evolving landscape of the DCIS treatment, it is important to optimize DCIS adjuvant treatment in this young subgroup of patients.

Strengths of the study include that patient’s data, including recurrence data, were well-kept in a prospectively maintained database. This is the first study in young women with DCIS to determine if their presentation mode would specifically affect their outcomes, providing further insights into the management of this rare entity.

The study is not without limitations. As a retrospective study, it was not possible to correlate in all cases whether the presenting symptom coincided with the site of DCIS or was related to DCIS. However, we were able to distinguish reliably from the clinical records if the patient had breast symptoms upon first consult. Interestingly, while patients in this group could present with breast pain [21], breast pain is generally not associated with breast cancer [22]. Another limitation was that there may be selection bias in the treatment regime. However, the treatment of these cases was individualised and discussed in the multidisciplinary meeting. There was also no statistical difference in the treatment regimens between the cases who presented with symptoms versus those who did not.

In conclusion, DCIS in young women is uncommon. They tend to present with symptoms and have a great likelihood of grade III tumour, compared to asymptomatic patients. Mode of presentation did not affect recurrence though this finding was based on a small sample size. Larger studies should be done to validate our findings. Treatment should be individualised based on patient’s tumor characteristics.