In recent years, the treatment paradigm for hormone receptor positive, HER2-negative disease has shifted from "chemotherapy for visceral disease" and "hormone therapy for bone disease" to "chemotherapy only for visceral crises or endocrine resistance". In recent years, CDK4/6 inhibitors have been added to the therapeutic arsenal. A meta-analysis of clinical trials of first-line metastatic CDK4/6 inhibitors showed an improvement in progression-free survival but an increase in toxicities compared to endocrine therapy alone. Other commonly used oral therapies for breast cancer are mTOR inhibitors and capecitabine. Other oral molecules will be added to the therapeutic arsenal in the coming years (e.g. alpelisib and tucatinib), each with specific toxicities.

Newer targeted therapies given in combination with endocrine therapies for breast cancer (eg with palbociclib, everolimus, and capecitabine) pose a challenge to health care providers because they are oral drugs. For "traditional" intravenous chemotherapy, patients must go to the hospital regularly, which allows close care by a team of doctors, pharmacists and nurses dedicated to breast cancer. On the other hand, for oral agents, monitoring is less systematic. Monitoring and managing the toxicities of oral treatments becomes a challenge. Suboptimal management of side effects can compromise patients' adherence to their treatment, have a negative impact on their side effects and increase costs for the healthcare system. Systematic follow-up is therefore necessary.

In the information age, public access to the Internet is increasing and most households in the province of Quebec now have access to the Internet, either on a smart phone, tablet or computer. Recent studies have shown that having a system to "self-report" side effects could even improve the survival of cancer patients and reduce costs. Apps allow patients to take an active role in their healthcare.

With the availability of an increasing number of oral therapies, monitoring the toxicities experienced by these patients is becoming a challenge and oncology teams need tools to help them ensure patient safety. At the same time, patients clearly want more information. The potential benefits and ease of use of web interfaces and patient portals for the management of oral therapy toxicities are appealing, but there is a lack of studies on them.

Inclusion Criteria:

• >=18 years of age
• metastatic breast cancer
• receiving oral chemotherapy (palbociclib, everolimus, or capecitabine)
• possess an smartphone, a tablet, or a personal compiter

Exclusion Criteria:

• cognitive impairments