Inclusion Criteria:

- Female greater than or equal to 18 years.

- Histologically confirmed breast adenocarcinoma with incurable progressing
local-regional or metastatic.

- ER and/or PR positivity of primary and/or secondary tumor.

- Patients must have measurable or evaluable disease.

- Evidence of disease progression or relapse while on or less than 6 months off
aromatase inhibitors or tamoxifen either in adjuvant or first line metastatic
setting.

- Postmenopausal

- Patients may have received up to one prior chemotherapy regimen for stage IV breast
cancer. Prior chemotherapy in the adjuvant and/or neoadjuvant setting is permitted.
Chemotherapy must be finished at least 2 weeks prior to enrollment.

- ECOG performance status <2

- Fasting cholesterol ≤300 mg/dL OR ≤7.75 mmol/LAND fasting triglycerides ≤ 2.5 x ULN
despite appropriate treatment.

- Patients must have adequate organ function as defined by the protocol.

- Stratification 1:

- HER2 positive in the primary or secondary tumor tissue

- Prior trastuzumab therapy is allowed but NOT required. However, trastuzumab
should be discontinued at least 3 weeks prior to enrollment.

- Stratification 2:

- HER2 negative in the primary or secondary tumor tissue

Exclusion Criteria:

- Patients receiving any other investigational agents.

- Prior exposure to lapatinib, everolimus, or other mTOR inhibitors.

- History of allergic reactions or hypersensitivity to compounds similar to everolimus,
lapatinib, or letrozole.

- Patients who have any severe and/or uncontrolled medical conditions that could affect
their participation such as:

- Left ventricular ejection fraction (LVEF) < 50%

- Unstable angina, symptomatic congestive heart failure, myocardial infarction
within 6 months, serious uncontrolled cardiac arrhythmia or any other clinically
significant cardiac disease.

- Severely impaired lung function as defined as spirometry and DLCO that is 50% of
the normal predicted value and/or O2 saturation that is ≤ 88% at rest on room
air.

- Uncontrolled diabetes

- Active or uncontrolled severe infection

- Patients with QTc interval > 0.47 seconds.

- Significant chronic or acute gastrointestinal disorder with diarrhea as a major
symptom.

- Prior exposure to more than 360 mg/m2 doxorubicin, more than 120 mg/m2mitoxantrone,
or more than 90 mg/m2idarubicin, or elevated baseline cardiac troponin I.

- Patients with active CNS metastasis and/or carcinomatous meningtitis. However,
patients with CNS metastasis who have completed a therapy and are clinically stable
for 3 weeks as defined as: (1) no evidence of new or enlarging CNS metastasis and (2)
off steroids and/or anticonvulsants.

- Patient is known to be HIV, Hepatitis B, or Hepatitis C-positive (these tests are not
required).

- Patients with current active hepatic or biliary disease (with exception of patients
with Gilbert's syndrome, asymptomatic gallstones, liver metastases or stable chronic
liver disease).

- Patients with INR ≥ 2 or PTT ≥ 2 x upper normal limit.

- Previous or current systemic malignancy other than breast cancer within the past 3
years other than carcinoma in situ of the cervix or basal/squamous carcinoma of the
skin.